Phased array antenna and method of manufacturing method

Abstract
A relatively small and inexpensive phased array antenna provided even if the number of radiators is increased to enhance the gain. The phased array antenna has a multilayer structure including layers where a large number of radiators (15), phase-shifting units (17) each for shifting the phase of a high-frequency signal transmitted/received by the corresponding radiator, and a distributing/synthesizing unit (14) are provided respectively. The phase-shifting circuits (17A to 17D) constituting the phase-shifting units (17) are driven by the respective driver units (12). A switch (17S) used for the phase-shifting unit is provided together with the other wiring pattern on the layer where the phase-shifting units (17) are provided.
Description




TECHNICAL FIELD




The present invention relates to a phased array antenna used for transmitting/receiving an RF signal such as a microwave to electrically adjust a beam radiation direction by controlling a phase supplied to each radiating element, and a method of manufacturing the antenna.




BACKGROUND ART




As a satellite tracking on-vehicle antenna or satellite borne antenna, a phased array antenna having many radiating elements arranged in an array has conventionally been proposed (see Technical Report AP90-75 of the Institute of Electronics, Information and Communication Engineers, and Japanese Patent Laid-Open No. 1-290301).




A phased array antenna of this type has a function of arbitrarily changing the beam direction by electronically changing the phase of a signal supplied to each radiating element.




As a means for changing the feed phase of each radiating element, a phase shifter is used.




As the phase shifter, a digital phase shifter (to be simply referred to as a phase shifter hereinafter) made up of a plurality of phase shift circuits having different fixed phase shift amounts is generally used.




The phase shift circuits are respectively ON/OFF-controlled by 1-bit digital control signals to combine the phase shift amounts of the phase shift circuits, thereby obtaining a feed phase of 0° to 360° by the whole phase shifter.




A conventional phased array antenna uses many components including semiconductor elements such as PIN diodes and GaAs FETs serving as phase shift circuits, and driver circuit components for driving the semiconductor elements.




The phase shifter applies a DC current or DC voltage to these switching elements to turn them on/off, and changes the transmission path length, susceptance, and reflection coefficient to generate a predetermined phase shift amount.




Recently in the field of low earth orbit satellite communications, communications at high data rates are required along with the wide use of the Internet and the spread of multimedia communications, and the gain of the antenna must be increased.




To implement communications at high data rates, the transmission bandwidth must be increased. Because of a shortage of the frequency resource in a low-frequency band, an antenna applicable to an RF band equal to or higher than the Ka band (about 20 GHz or higher) must be implemented.




More specifically, an antenna for a low earth orbit satellite tracking terminal (terrestrial station) must satisfy technical performance:




Frequency: 30 GHz




Antenna gain: 36 dBi




Beam scanning range: beam tilt angle of 50° from front direction




To realize this by a phased array antenna, first,




the aperture area: about 0.13 m


2


(360 mm×360 mm) is needed.




In addition, to suppress the side lobe, radiating elements must be arranged at an interval of about ½ wavelength (around 5 mm for 30 GHz) to avoid generation of the grating lobe.




To set a small beam scanning step and minimize the side lobe degradation caused by the quantization error of the digital phase shifter, the phase shift circuit used for the phase shifter is desirably made up of at least 4 bits (22.5° for the minimum-bit phase shifter).




The total number of radiating elements and the number of phase shift circuit bits used for a phased array antenna which satisfies the above conditions are given by




 Number of elements for the phase shift circuit: 72×72=about 5,000






Number of phase shift circuit bits: 72×72×4=about 20,000 bits






When a high-gain phased array antenna applicable to an RF band is to be implemented by, e.g., a phased array antenna disclosed in Japanese Patent Laid-Open No. 1-290301 shown in

FIG. 18

, the following problems occur.




That is, in such a conventional phased array antenna, switching elements serving as discrete components are individually mounted on a substrate formed with wiring patterns, thereby forming a phase shifter, as shown in FIG.


18


.




However, a gain is determined depending on the area of a phased array antenna, and its arrangement interval is determined depending on the frequency band in which the antennas are to be used, as described above. Accordingly, if a high-gain phased array antenna used in a higher RF band is formed, the number of phase shifters greatly increases in accordance with a large increase in number of radiating elements, thereby greatly increasing the number of mounted components.




This increases a time required for mounting these components on the substrate and the manufacturing lead time, thereby increasing manufacturing cost.




The present invention has been made to solve the above problems, and has as its object to provide a high-gain phased array antenna applicable to an RF band.




DISCLOSURE OF INVENTION




To achieve the above object, in a phased array antenna according to the present invention, radiating elements and phase shifters are individually formed on a radiating element layer and phase control layer, respectively, and both layers are coupled by a first coupling layer to form a multilayered structure as a whole. A distribution/synthesis unit is formed on a distribution/synthesis layer, and the phase control layer and distribution/synthesis layer are coupled by a second coupling layer to form the multilayered structure as a whole. Therefore, the radiating elements and distribution/synthesis unit are eliminated from the phase control layer, thereby reducing an area in the phase control layer which is to be occupied by the radiating element and distribution/synthesis unit.




The phase control layer further has a multilayered structure in which a plurality of control signal lines for controlling the phase shifters are formed on different layers in the phase control layer. This reduces an area, which is to be occupied by the control signal lines, on the layer on which the phase shifters are formed.




The phase control layer uses a micromachine switch as an RF switch included in the phase shifter, and a number of micromachine switches are simultaneously formed by a semiconductor device manufacturing process. This can make the entire phase shifter small.




For this reason, the area of the phase control layer which defines the area of the radiating element layer can be reduced, many radiating elements are arranged, in units of several thousands, at an interval (around 5 mm) which is optimal for an RF signal of, e.g., about 30 GHz. This can implement a high-gain phased array antenna applicable to an RF band.




In addition, the switches used in each phase shifter are simultaneously formed on a phase control layer (a single substrate). Therefore, as compared to a case wherein the circuit components are individually mounted as in the prior art, the numbers of mounting components, the numbers of connections, and the numbers of assembling processes can decrease, thereby reducing the manufacturing cost of the whole phased array antenna.




Further, since a driver unit simultaneously switches the control signals output to the phase shift circuits, the phase amounts of the radiating elements set in the phase shifters are simultaneously changed, thereby instantaneously changing a radiation beam direction.




Furthermore, since the driver unit for controlling the phase shifter is comprised of a flip chip which can be formed in a small area, no space in which the driver unit is to be arranged is required, thereby forming a relatively small phased array antenna.











BRIEF DESCRIPTION OF DRAWINGS





FIG. 1

is a block diagram of a phased array antenna according to an embodiment of the present invention;





FIG. 2

is a block diagram of a driver unit;





FIG. 3

is a block diagram of a phase shifter and a phase controller;





FIG. 4

is a view for explaining a multilayered substrate structure;





FIG. 5

is a view showing a multilayered substrate structure according to another embodiment of the present invention;





FIG. 6

is a view showing a multilayered substrate structure according to still another embodiment of the present invention;





FIG. 7

is an explanatory view schematically showing the arrangement on a phase control layer;





FIG. 8

is a perspective view showing a structure of a switch;





FIG. 9

is the first view showing a process for simultaneously forming micromachine switches on the phase control layer;





FIG. 10

is the second view showing the process for simultaneously forming the micromachine switches on the phase control layer;





FIG. 11

shows views for explaining an example of mounting a switch;





FIG. 12

shows views for explaining another example of mounting the switch;





FIG. 13

shows views of the circuit arrangement in Example 1;





FIG. 14

shows views of the circuit arrangement in Example 2;





FIG. 15

shows views of the circuit arrangement in Example 3;





FIG. 16

shows views of the circuit arrangement in Example 4;





FIG. 17

shows views of the circuit arrangement in Example 5; and





FIG. 18

is a view for explaining a conventional phased array antenna.











BEST MODE OF CARRYING OUT THE INVENTION




The present invention will be described below with reference to the accompanying drawings.





FIG. 1

is a block diagram of a phased array antenna


1


according to an embodiment of the present invention.




In the following description, a phased array antenna is used as an RF signal transmission antenna. However, the phased array antenna is not limited to this, and can be used as an RF signal reception antenna for the same operation principle based on the reciprocity theorem.




In addition, when a whole antenna is made up of a plurality of subarrays, the present invention may be applied to a phased array antenna of each subarray.





FIG. 1

is a view for explaining the arrangement of the phased array antenna


1


. Referring to

FIG. 1

, the phased array antenna


1


is made up of a multilayered substrate unit


2


on which antenna radiating elements, phase control circuits, and the like are mounted on a multilayered substrate, a feeder


13


for feeding RF power to the multilayered substrate unit


2


, a control unit


11


for controlling the phase of each radiating element of the multilayered substrate unit


2


, and a driver unit


12


for individually driving phase shifters.




In

FIG. 1

, m×n (m and n are integers of 2 or more) radiating elements


15


are arranged in an array, and RF signals are supplied to the radiating elements


15


from the feeder


13


via a distribution/synthesis unit


14


, strip lines


16


, and phase shifters


17


.




Note that, the radiating elements


15


may be arranged in a rectangular matrix shape or any other shape such as a triangular shape.




Many control signal lines


53


(in the aforementioned example, the total number of phase shifters


17


is about 5,000 units) for connecting the phase shifters


17


to the phase shift units


16


and the active regions


12


to the phase shifters


17


are simultaneously formed on the phased array antenna


1


by photolithography and etching.




The control unit


11


calculates the feed phase shift amount of each radiating element


15


on the basis of a desired beam radiation direction.




The calculated phase shift amounts of respective calculated radiating elements


15


are distributed from the control unit


11


to the p driver units


12


by control signals


11




i


to


11




p


(one of these control signals may be called as a control signal


11




i


). In one driver unit


12


, the phase shift amounts of the q radiating elements


17


are serially input. In this case, p×q is basically equal to the total number of m×n radiation elements, but becomes slightly larger than the number of total radiation elements depending on the number of output terminals of the driver units


12


.





FIG. 2

is a block diagram of the driver unit


12


.




The driver unit


12


is comprised of a data distributor


41


and q phase controllers


42


arranged for the respective phase shifters


17


.




The driver unit


12


serially receives the phase shift amounts of the q radiating elements


15


.




The data distributor


41


distributes the phase shift amounts of the q radiating element


15


included in a control signal


11




i


to the q phase controllers


42


respectively connected to the phase shifters


17


.




Then, the phase shift amounts of the radiating elements


15


are set in corresponding phase controllers


42


.




As shown in

FIG. 1

, the control unit


11


outputs a trigger signal Trg to each driver unit


12


.




The trigger signal Trg is input to each phase controller


42


of the driver unit


12


, as shown in FIG.


2


.




The trigger signal Trg determines a timing in which each phase shift amount set in the phase controller


42


is designated and output to a corresponding phase shifter


17


.




Therefore, after the phase shift amounts are respectively set in the phase controllers


42


, the controller


11


outputs the pulse-like trigger signal Trg to simultaneously update the feed phase shift amounts to the respective radiating elements


15


, thereby instantaneously changing the beam radiation direction.




The phase shifter


17


arranged for each radiating element


15


and the phase controller


42


of the driver unit


12


will be described with reference to FIG.


3


.





FIG. 3

is a block diagram showing the phase shifter


17


and the phase controller


42


.




In this case, the phase shifter


17


is made up of four phase shift circuits


17


A to


17


D having different phase shift amounts of 22.5°, 45°, 90°, and 180°.




The phase shift circuits


17


A to


17


D are connected to a strip line


16


for propagating an RF signal from the distribution/synthesis unit


14


to the radiating element


15


.




In particular, each of the phase shift circuits


17


A to


17


D comprises a switch


17


S.




By switching the internal switches of the switch


17


S, a predetermined feed phase shift amount (to be described below) is supplied.




The phase controller


42


for individually controlling the switches


17


S of the respective phase shift circuits


17


A to


17


D is constituted by latches


43


A to


43


D respectively arranged for the phase shift circuits


17


A to


17


D.




The data distributor


41


of the driver unit


12


outputs control signals


41


A to


41


D to the latches


43


A to


43


D which constitute the phase controller


42


to give the phase controller


42


the phase shift amount of the radiating element


15


.




Therefore, the inputs D of the latches


43


A to


43


D receive the control signals


41


A to


41


D, respectively.




The inputs CLK of the latches


43


A to


43


D receive the trigger signal Trg output from the control unit


11


.




The latches


43


A to


43


D latch the control signals


41


A to


41


D at the leading (or trailing) edge of the trigger signal Trg, and output the outputs Q to the switches


17


S of the corresponding phase shift circuits


17


A to


17


D.




The ON/OFF states of the switches


17


S of the phase shift circuits


17


A to


17


D are determined in accordance with the states of the latched control signals


41


A to


41


D.




In this fashion, the phase shift amounts of the phase shift circuits


17


A to


17


D are set to set the total phase shift amount of the phase shifter


17


. Accordingly, a predetermined feed phase shift amount is given to an RF signal propagating through the strip line


16


.




Note that the switches


17


S may be sequentially switched by always outputting the trigger signal Trg, i.e., always keeping the trigger signal Trg at high level (or low level). In this case, the entire phase shifter


17


is not simultaneously switched but is partially switched, which avoids a hit of a radiation beam.




If the output voltages or currents of the latches


43


A to


43


D are not high enough to drive the switches


17


S, voltage amplifiers or current amplifiers may be arranged on the output sides of the latches


43


A to


43


D.




The substrate arrangement of the phased array antenna according to this embodiment will be described next with reference to FIG.


4


.





FIG. 4

is a view for explaining the multilayered substrate unit


2


, which shows perspective views of layers and schematic views of sections.




The layers are patterned by photolithography, etching, or printing and stacked and integrated into a multilayer.




The stacking order of the respective layers is not necessarily limited to the one shown in FIG.


4


. Even if the stacking order partially changes due to deletion or addition depending on the electrical/mechanical requirement, the present invention is effective.




A branch-like strip line


23


for distributing RF signals applied from the feeder


13


is formed on a distribution/synthesis layer


39


.




The strip lines


23


can use a tournament scheme in which two branches are repeated or a series distribution scheme for gradually branching the main line in comb-like teeth.




A dielectric layer


38


A and a ground layer


39


A made of a conductor are added outside the distribution/synthesis layer


39


in accordance with a mechanical design condition such a mechanical strength or an electrical design condition such as unnecessary radiation suppression.




A coupling layer


37


(second coupling layer) is formed above the distribution/synthesis layer


39


through a dielectric layer


38


.




The coupling layer


37


is comprised of a conductive pattern in which holes, i.e., coupling slots


22


are formed on a ground plane.




A phase control layer


35


is formed above the coupling layer


37


through a dielectric layer


36


.




The strip line


16


, the phase shifters


17


, and the control signal lines


53


for connecting the phase shifters


17


to the driver units


12


are formed on the phase control layer


35


, and a large number of them (the total number of phase shifters


17


is about 5,000 in the example as described above) are simultaneously formed by photolithography or etching.




A coupling layer


33


(first coupling layer) having coupling slots


21


as in the coupling layer


37


is formed above the phase control layer


35


through a dielectric layer


34


.




A radiating element layer


31


having the radiating elements


15


is formed above the coupling layer


33


through a dielectric layer


32


.




A passive element layer


31


A having passive elements


15


A is formed above the radiating element layer


31


through a dielectric layer


31


B.




However, the passive elements


15


A are added to widen the band, and may be arranged as needed.




Each of the dielectric layers


31


B,


32


,


38


, and


38


A is made of a material having low relative dielectric constant of about 1 to 4, e.g., a printed board, glass substrate, or foaming material. These dielectric layers may be spaces (air layers).




As the dielectric layer


36


, a semiconductor substrate (silicon, gallium arsenide, or the like) as well as a glass substrate can be used. Alternatively, a circuit board such as a ceramics board or a printed board may be used.




In particular, since the switches of the phase shifter


17


are simultaneously formed on the phase control layer


35


as described above, the dielectric layer


34


may be made of a space (air layer).




For the sake of descriptive simplicity, the respective layers constructing the multilayered substrate portion


2


are separately described in FIG.


4


. However, a layer adjacent to each of the dielectric layers


31


B,


32


,


34


,


36


,


38


, and


38


A, e.g., the radiating element layer


31


or dielectric layer


32


is realized by patterning it on one or two sides of the dielectric layer.




The aforementioned dielectric layer is not made of a single material and may have an arrangement in which a plurality of materials are stacked.




In the antenna having the multilayered structure described above, the RF signal from the feeder


13


(not shown in

FIG. 4

) propagates from the strip line


23


of the distribution/synthesis layer


39


to the strip lines of the phase control layer


35


via the coupling slots


22


of the coupling layer


37


.




The RF signal is then given a predetermined feed phase shift amount in the phase shifter


17


and propagates to the radiating elements


15


of the radiating element layer


31


via the coupling slots


21


of the coupling layer


33


to radiate from each radiating element


15


to a predetermined beam direction.




In this manner, in the present invention, the radiating elements


15


and the phase shifters


17


are individually formed on the radiating element layer


31


and the phase control layer


35


, respectively, and both layers are coupled by the coupling layer


33


to form the multilayered structure as a whole.




In addition, the distribution/synthesis unit


14


is individually formed on the distribution/synthesis layer


39


, and the phase control layer


35


and distribution/synthesis layer


39


are coupled by the coupling layer


37


to form the multilayered structure as a whole.




This reduces the area, of the phase control layer


35


, which is to be occupied by the radiating elements


15


and distribution/synthesis unit


14


even if the number of radiating elements


15


increases in order to improve the gain.




Accordingly, one phase shifter


17


is formed in a relatively small area. For this reason, e.g., for the RF signal of about 30 GHz, the radiating elements


15


can be arranged at an optimum interval of around 5 mm, thereby realizing the high-gain phased array antenna applicable to an RF band.




In addition, an angle in which the grating lobe is generated is made large by realizing the optimum element interval, thereby scanning a beam within a wide range centered on the front direction of the antenna.




In the phase control layer


35


, the switches


17


S used in the phase shift circuits


17


A to


17


D are simultaneously formed together with the wiring patterns (i.e., the first strip line


16


, second strip line, and control signal lines


53


) of the phase control layer


35


. Thus, as compared to the case in which the circuit components are individually mounted as in the prior art, the number of separately mounted components, the number of connections, and the number of assembling processes can be decreased, thereby reducing the manufacturing cost of the whole phased array antenna.




As each strip line


16


used in the present invention and the strip line used in each phase shifter


17


, a triplet type, coplanar type, slot type, or the like as well as a microstrip type distributed constant line can be used.




As the radiating element


15


, a printed dipole antenna, slot antenna, aperture element or the like as well as a patch antenna can be used.




In particular, the opening of the coupling slot


21


of the coupling layer


33


is made large, which is usable as a slot antenna. In this case, the coupling layer


33


also serves as the radiating element layer


31


, and the radiating element layer


31


and passive element layer


31


A can be omitted.




In place of the coupling slots


21


, conductive feed pins for connecting the strip lines


16


of the phase control layer


35


and the radiating elements


15


may be used to couple the RF signals.




Further, in place of the coupling slots


22


, conductive feed pins projecting from the strip lines of the phase control layer


35


to the dielectric layer


38


through holes formed in the coupling layer


37


may be used to couple the RF signals.




The same function as that of the distribution/synthesis layer


39


can also be realized even if a radial waveguide is used.





FIG. 5

is a view for explaining the arrangement of the present invention when using the radial waveguide.




In this case, a distribution/synthesis function is realized by a dielectric layer


38


, ground layer


39


A, and probe


25


of a multilayered substrate unit


2


shown in

FIG. 5

, and a distribution/synthesis layer


39


required in

FIG. 4

can be omitted.




In this case, the dielectric layer


38


is also made of a printed board, glass substrate, foaming agent, or space (air layer). As the ground layer


39


A, the copper foil on a printed board may be directly used, or a metal plate or a metal enclosure for enclosing all the side surfaces of the dielectric


38


may be separately arranged.




The present invention can also be applied to a space-fed phased array antenna.





FIG. 6

shows the arrangement of a reflection-type space-fed phased array antenna as an example.




A phased array antenna


1


shown in

FIG. 6

is made up of a feeder


13


, a radiation feeder


27


having a primary radiation unit


26


, a multilayered substrate unit


2


, and a control unit


11


(not shown). In this structure, the multilayered substrate unit


2


has a structure different from that shown in

FIG. 4

, which is constructed by a radiating element layer


31


, dielectric layer


32


, coupling layer


33


, dielectric layer


34


, and phase control layer


35


.




The function of the distribution/synthesis unit


14


shown in

FIG. 1

is realized by the primary radiation unit


26


so that a distribution/synthesis layer


39


is excluded from the multilayered substrate unit


2


.




In the phased array antenna


1


, an RF signal radiated from the radiation feeder


27


is temporarily received by each radiating element


15


on the radiating element layer


31


, and is coupled to each phase shifter


17


on the phase control layer


35


via the coupling layer


33


. After the phase of the RF signal is controlled by each phase shifter


17


, the RF signal propagates to each radiating element


15


again via the coupling layer


33


, and radiates from each radiating element


15


in the predetermined beam direction.




The present invention is effective even for the space-fed phased array antenna as described above which includes no distribution/synthesis layer


39


in the multilayered substrate unit


2


.




An example of the arrangement of the phase control layer


35


will be explained next with reference to FIG.


7


.





FIG. 7

is an explanatory view schematically showing an arrangement on the phase control layer


35


.




In a multilayered structure region on the phase control layer


35


, many phase shifters


17


are arranged in an array, and the wiring patterns of the control signal lines


53


are formed.




The plurality of driver units


12


each made up of a flip chip


51


are arranged in a region on the phase control layer


35


except for the multilayered structure region.




The flip chip


51


is a chip for bonding by using a connection terminal formed on a chip or board (i.e., for face-down bonding) without any lead wire such as a wire lead or a beam lead.




If the flip chip


51


is mounted by a bump scheme, bumps


52


are formed on the chip electrodes as connection terminals to connect to the wiring lines of the phase control layer


35


directory or through an anisotropy conductive sheet.




If the driver unit


12


is made up of the flip chip


51


, the bumps


52


are formed on the input electrodes of the data distributor


11




i


, the common electrode of the inputs CLK of latches


43


which constitute each phase controller


42


, and the electrodes of the outputs Q of the latches


43


.




In particular, the bumps


52


serving as the outputs Q of the latches


43


are individually connected to one of the phase shift circuits


17


A to


17


D of the phase shifter


17


by the control signal lines


53


formed on the phase control layer


35


.




Since the bumps


52


are formed not only around the chip but also on the entire surface of the chip, the chip size does not always increase even if the number of electrodes increases, thereby increase the packaging density of the IC.




For this purpose, even if, an increase in number of the radiating elements


15


increases the total number of bits of the phase shifter


17


to be controlled in order to improve the gain of an antenna, the driver unit


12


for driving the phase shifter


17


is comprised of the flip chip


51


, thereby suppressing an increase in size of the phased array antenna.




In addition, since the number of chips mounted on the phase control layer


35


can be decreased, a time required for arranging the chips at predetermined positions can be reduced, thereby suppressing an increase in manufacturing lead time.




Assume that, an example, in arranging the phased array antenna, the number of radiating elements


15


is set at 5,000 to obtain the gain of 36 dBi, and each phase shift circuit used in each phase shifter


17


is made up of 4 bits to obtain many beam scanning steps. In this case, total number of phase shift circuit bits is 20,000.




In this case, the chips corresponding to the 20,000 terminals are required for constructing the driver units


12


. However, all the phase shifters


17


can be driven by using the ten flip chips


51


each having 2,000 terminals.




The flip chips


51


are arranged on the two sides of the phase control layer


35


in the column direction.




The flip chips


51


on the left side control the left half of the phase shifters


17


arranged in the row direction while the flip chips


51


on the right side control the right half of the phase shifters


17


arranged in the row direction.




The phase control layer


35


has a two-layered structure, and the control signal line


53


for connecting the bumps


52


of the flip chip


51


to the respective phase shift circuits


17


A to


17


D are separately wired on the two layers of the phase control layer


35


.




The control signal lines


53


formed on a layer different from the flip chips


51


or the phase shift circuits


17


A to


17


D are connected to the flip chips


51


or the phase shift circuits


17


A to


17


D through via holes (electrical connecting holes) formed in a board.




With this structure, the maximum width of the bundle of the control signal lines


53


(see

FIGS. 13

to


17


) is made small, thereby reducing the area of the phase control layer


35


which is to be prepared for the control signal lines


53


.




This makes the phased array antenna small and decreases the intervals between the radiating elements


15


, thereby increasing the radiation beam range.




If the number of control signal lines


53


is small, or the width of each control signal line


53


is made small, the phase control layer


35


is not required to have the multilayered structure, and all the control signal lines


53


can be wired on the single layer.




In this example, the flip chip


51


in the bump scheme has been explained. However, bumps may be formed on a board on which the flip chips


51


is to be mounted (the phase control layer


35


in this case) in place of forming the bumps


52


on the chip, and the flip chips


51


are mounted as in the manner described above.




A structure of the switch


17


S will be described with reference to

FIG. 8

while using an example of practical sizes.





FIG. 8

is a perspective view showing the structure of the switch.




This switch


17


S is comprised of a micromachine switch for short-circuiting/releasing strip lines


62


and


63


by a contact (small contact)


64


. The “micromachine switch” means a small switch suitable for integration by a semiconductor device manufacturing process.




The strip lines


62


and


63


(about 1 μm thick) are formed on a substrate


61


at a small gap. The contact


64


(about 2 μm thick) is supported by a support member


65


above the gap so as to freely contact the strip lines


62


and


63


. The distance between the lower surface of the small contact


64


and the upper surfaces of the strip lines


62


and


63


is about 4 μm. The level of the upper surface of the small contact


64


from the upper surface of the substrate


61


, i.e., the height of the whole micromachine switch is about 7 μm.




A conductive electrode


66


(about 0.2 μm thick) is formed at the gap between the strip lines


62


and


63


on the substrate


61


. The height (thickness) of the electrode


66


is smaller than that of the strip lines


62


and


63


.




The operation of the switch will be explained.




The electrode


66


receives an output voltage (e.g., about 10 to 100 V) from a corresponding one of the driver circuits


19


A to


19


D.




When a positive output voltage is applied to the electrode


66


, positive charges are generated on the surface of the electrode


66


. At the same time, negative charges appear on the surface of the facing contact


64


(to be referred to as a lower surface hereinafter) by electrostatic induction, and are attracted to the strip lines


62


and


63


by the attraction force between the




Since the contact


64


is longer than the gap between the strip lines


62


and


63


, the contact


64


contacts both the strip lines


62


and


63


, and the strip lines


62


and


63


are electrically connected in a high-frequency manner through the contact


64


.




When application of the output voltage to the electrode


66


stops, the attraction force disappears, and the contact


64


returns to an original apart position by the support member


65


to release the strip lines


62


and


63


.




In the above description, the output voltage is applied to the electrode


66


without applying any voltage to the contact


64


. However, the operation may be reversed.




That is, the output voltage of the driver circuit may be applied to the contact


64


via the conductive support member


65


without applying any voltage to the electrode


66


. Even in this case, the same effects as those described above can be attained.




At least the lower surface of the contact


64


may be formed from a conductor so as to ohmic-contact the strip lines


62


and


63


. Alternatively, an insulating thin film may be formed on the lower surface of the conductive member so as to capacitively couple the strip lines


62


and


63


.




In the micromachine switch, the contact


64


is movable. When the phase control layer


35


is formed on a multilayered substrate, like a phased array antenna, a space for freely moving the contact


64


must be defined.




In this manner, since the micromachine switch is used as the switching element for controlling the feed phase, the power consumption at the semiconductor junction can be eliminated as compared with the use of a semiconductor device such as a PIN diode. This makes it possible to reduce the power consumption to about {fraction (1/10)}.




A formation means of circuit components of the phase shifter


17


incorporated in the phase control layer


35


, the strip line


16


, and the control signal line


53


will be described next.





FIGS. 9 and 10

show a case in which the control signal lines


53


(corresponding to wiring lines


220


and


221


) and the switch


17


S (micromachine switch in this case) are simultaneously formed by applying a semiconductor element manufacturing process, and particularly, by applying a wiring means by a thin film as an example of the means for forming a circuit component.




First, a glass substrate


201


whose surface is accurately polished to have flatness Ra=about 4 to 5 nm is prepared, and a photoresist is applied onto the glass substrate


201


.




The glass substrate


201


is patterned by known photolithography, and a resist pattern


202


having grooves


220


A at predetermined portions is formed on the glass substrate


201


, as shown in FIG.


9


(


a


).




As shown in FIG.


9


(


b


), a metal film


203


made of chromium, aluminum or the like is formed on the resist pattern


202


having the grooves


202


A by sputtering.




The resist pattern


202


is removed by a method, e.g., dissolving it in an organic solvent to selectively remove (lift off) the metal film


203


on the resist pattern


202


, thereby forming the wiring patterns


220


on the glass substrate


201


, as shown in FIG.


9


(


c


).




As shown in FIG.


9


(


d


), silicon oxide or the like is grown on the glass substrate


201


by sputtering so as to cover the wiring patterns


220


, thereby forming an insulating film


204


.




Then, as shown in FIG.


9


(


e


), a photoresist


205


is applied on the insulating film


204


and patterned by known photolithography, thereby forming, as shown in FIG.


9


(


f


), a resist pattern


205


having grooves


221


A,


62


A,


63


A, and


66


A, and an openings (not shown). The grooves


221


A are formed at predetermined positions corresponding to wiring lines which are to be formed; the grooves


62


A and


63


A, at positions of the strip lines


62


and


63


, respectively; the groove


66


A, at a predetermined position corresponding to the electrode


66


; and the opening, at a position corresponding to a column portion (


65


A shown in FIG.


10


(


l


)) of the support member


65


of the switch


17


S.




As shown in FIG.


10


(


g


), a metal film


206


made of, e.g., chromium or aluminum is formed by sputtering on the resist pattern


205


so as to bury the grooves


62


A,


63


A,


66


A, and


221


A and the opening.




The resist pattern


205


is removed by dissolving it in the organic solvent so that, as shown in FIG.


10


(


h


), the wiring patterns


221


and the strip lines


62


and


63


of the switch


17


S, the electrode


66


, and the columnar electrode (not shown) of the support member


65


are simultaneously formed.




Next, as shown in FIG.


10


(


i


), a metal film


209


made of gold or the like is selectively grown on the strip lines


62


and


63


.




With this processing, the wiring resistance decreases to reduce the propagation loss in an RF band while an air gap is ensured between the contact


64


and the electrode


66


to avoid short-circuiting therebetween even if the contact


64


is displaced to a position where the strip lines


62


and


63


are electrically connected in a high-frequency manner.




As shown in FIG.


10


(


j


), polyimide or the like is applied, dried, and harden on the entire surface of the substrate


201


to form a sacrificial layer


211


about 5 to 6 μm thick.




An opening (not shown) is formed at the position, where the column of the support member


65


of the switch


17


S is to be formed, by known photolithography and etching to form a column portion made of a metal so as to fill the opening with it.




Then, as shown in FIG.


10


(


k


), the arm portion of the support member


65


and the contact


64


are formed by lift-off at a position across the column portion and a portion above the strip lines


62


and


63


.




With this processing, the arm portion of the support member


65


and the contact


64


are electrically connected to the column portion of the support member


65


.




As shown in FIG.


10


(


l


), only the sacrificial layer


211


is selectively removed by dry-etching using oxygen gas plasma.




With this processing, the aforementioned micromachine switch (switch


17


S) (

FIG. 8

) and the wiring patterns


220


and


221


of the control signal lines


53


are simultaneously formed on the glass substrate


201


, i.e., the phase control layer


35


.




The above example has described the means for simultaneously forming the wiring patterns


220


and


221


and switch


17


S on the glass substrate. However, the means for forming the circuit components of the phase shifter


17


of the present invention is not limited to this, and the switch


17


S can be separately formed after forming the wiring patterns of the control signal lines


53


on the glass substrate in advance.




A ceramics board made of aluminum or the like or a semiconductor substrate can also be used in place of the glass substrate


201


.




As described above, in the present invention, the circuit components of the phase shifter


17


, the strip line


16


, and the control signal lines


53


are simultaneously formed on a single surface of the phase control layer


35


in the single process by using a semiconductor device manufacturing process. This reduces the number of components to be individually mounted and the number of connections, thereby reducing the number of assembling processes. As a result, the manufacturing cost of the whole phased array antenna can be greatly reduced.




A method of mounting the switch


17


S used in the phase shifter


17


will be described next with reference to FIG.


11


.




In the present invention, the many switches


17


S of the phase shifter


17


are simultaneously formed on the single substrate in the phase control layer


35


which is stacked in the multilayered structure.





FIG. 11

shows views for explaining an example of mounting the switch


17


S by exemplifying a case wherein a mounting space for the switch


17


S is formed by a spacer serving as a separate component, in which FIG.


11


(


a


) shows a case wherein a space is ensured above the switches


17


S, and FIG.


11


(


b


) shows a case wherein a space is ensured below the switches


17


S.




In FIG.


11


(


a


), the phase control layer


35


is formed on the dielectric layer


36


, and the switches


17


S used in the phase shifter


17


(micromachine switches in this case) is formed at once on the phase control layer


35


.




As the dielectric layer


36


, a semiconductor substrate (silicon, gallium arsenide, or the like) as well as the glass substrate (relative dielectric constant: about 4 to 8) can be used. Alternatively, a circuit board such as a ceramics board or a printed board may be used.




The thin film of the phase control layer


35


is formed by vacuum deposition or sputtering, and the pattern is formed by using a metal mask or photoetching.




As described above, when the switch


17


S having a movable portion such as the contact


64


of the micromachine switch is used, a space for mounting the switch


17


S need be ensured.




In this example, the mounting space has a space


34


S (internal space) formed between the phase control layer


35


and coupling layer


33


, and the space


34


S is formed by forming a spacer


34


A serving as a separate component.




In this case, the spacer


34


A may be arranged below the coupling slot


21


. With this arrangement, a space immediately under the coupling slot


21


, which is generally an unused region, also serves as a region in which the spacer


34


A is arranged, thereby reducing the area occupied by the spacer


34


A.




As the spacer


34


A, a material having high relative dielectric constant of about 5 to 30 such as alumina may be used and arranged under the coupling slot


21


. Thus, the coupling slot


21


and the strip line


24


on the phase control layer


35


are efficiently coupled in a high-frequency manner.




Although not shown in

FIG. 11

, the spacer


34


A may be formed from a conductor and arranged on the upper portion of a via hole (electrical connecting hole) separately formed in the dielectric layer


36


, and may be electrically connected to ground patterns, e.g., the conductive patterns of the coupling layers


33


and


37


.




In FIG.


11


(


b


), as compared to FIG.


11


(


a


) described above, the stacking order of the dielectric layer


36


, phase control layer


35


, and dielectric layer


34


is reversed.




More specifically, the upper side of the dielectric layer


36


closely contacts the coupling layer


33


, the spacer


34


A is formed between the phase control layer


35


on the lower side of the dielectric layer


36


and coupling layer


37


, and the dielectric layer


34


is formed by the space


34


S.




Therefore, the micromachine switch of the switch


17


S has a shape enough to ensure a space


34


S below the phase control layer


35


.




Another method of mounting the switch


17


S used in the phase shifter


17


will be described next with reference to FIG.


12


.





FIG. 12

shows views for explaining another example of mounting the switch


17


S, in which a mounting space for the switch


17


S is formed by various types of members.




FIG.


12


(


a


) shows a case wherein the space


34


S serving as the mounting space for the switch


17


S is formed by a dielectric film


34


C.




In this case, after a dielectric film is added on the sacrificial layer


211


used in forming the switch


17


S, the additive dielectric film and a part of the sacrificial layer


211


are selectively removed, thereby forming the dielectric film


34


C having a thickness larger than the height of the switch


17


S.




By using a photosensitive adhesive as the dielectric film


34


C, it can also serve as an adhesive in the sequential substrate stacking process.




As will be described later in Example 3, the dielectric film


34


C may be made thin, and the height required for the dielectric layer


34


may be made up for a substrate


34


D (not shown in FIG.


12


).




FIG.


12


(


b


) shows a case wherein the space


34


S serving as the mounting space for the switch


17


S is formed by forming the wiring pattern conductor on the phase control layer


35


thick. In this case, if the switch


17


S has, e.g., the height of 7 μm as described above, the conductive may have the thickness of about 10 μm.




In a method of forming the wiring pattern conductor thick, the switch


17


S is protected and plated thick with a metal by electrolytic plating or the like.




As the wiring pattern conductor, the strip line


16


having a relatively large width or a spacer-dedicated wiring pattern having a large area is used which is separately formed, thereby obtaining a stable mounting space


34


S.




FIG.


12


(


c


) shows a case wherein the space


34


S serving as the mounting space for the switch


17


S is formed by using a substrate


34


E having a cavity (space)


34


F.




In this case, the cavity


34


F is formed in the substrate


34


E so as to correspond to the position of the switch


17


S mounted on the phase control layer


35


.




The substrate


34


E is stacked between the phase control layer


35


and coupling layer


33


as the dielectric layer


34


.




As the substrate


34


E, a dielectric substrate having a low dielectric constant (relative dielectric constant: about 1 to 4) or a high dielectric constant (relative dielectric constant: about 5 to 30) is used in accordance with the design condition.




The cavity


34


F may be formed by cutting the surface of the substrate


34


E by machining. Alternatively, the cavity


34


F may be formed by forming a through hole by punching or the like.




After a photosensitive resin is applied on an organic substrate, the resin corresponding to the cavity


34


F may be removed by exposing and developing processes. Various types of the formation methods are usable.




EXAMPLES




Examples 1 to 5 (examples of arrangements for each radiating element) will be described below with reference to

FIGS. 13

to


17


, in which the present invention is applied to a 30-GHz phased array antenna.




A case wherein a phase shifter


17


is made up of four phase shift circuits


17


A to


17


D having different phase shift amounts of 22.5°, 45°, 90°, and 180° will be described below.




Assuming that micromachine switches are used as the switching elements of the phase shift circuits


17


A to


17


D.




Example 1 will be described first with reference to FIG.


13


.





FIG. 13

shows views of a circuit arrangement of Example 1, in which FIG.


13


(


a


) is a diagram showing a circuit arrangement in a phase shifter formation region, FIG.


13


(


b


) is a schematic view showing a multilayered structure, and FIG.


13


(


c


) is an enlarged view showing the arrangement of a control line layer portion


53


A in a phase control layer


35


.




A phase shifter formation region


18


is a region in which a phase shifter


17


arranged in correspondence with a radiating element


15


is formed on the phase control layer


35


, which is a substantially square (5 mm×5 mm), as shown in FIG.


13


(


a


).




In the phase shifter formation region


18


, a strip line


16


is formed to connect the upper portion of a coupling slot


22


to the lower portion of a coupling slot


21


.




Phase shift circuits for 22.5°, 45°, 90°, and 180° are arranged midway along the strip lines


16


.




Control signal lines


53


extending from a driver unit


12


to each phase shifter


17


arrayed in a predetermined direction (the row direction in

FIG. 7

) are closely arranged on one side portion of the region


18


, and are formed like a bundle.




Phase shifters


17


A to


17


D are simultaneously formed on one surface of a single substrate (glass substrate) as the phase control layer


35


.




The circular radiating element


15


(broken narrow line shown in FIG.


13


(


a


)) having a diameter of 2.5 mm to 4 mm is arranged on a radiating element layer


31


above the coupling slot


21


.




FIG.


13


(


b


) schematically shows the multilayered structure in Example 1, and the same reference numerals as in

FIG. 11

denote the same parts.




Note that FIG.


13


(


b


) schematically shows the multilayered structure, but does not show a specific section in FIG.


13


(


a


).




The multilayered structure of this example is obtained by sequentially stacking from the bottom to top in FIG.


13


(


b


), a ground layer


39


A, a dielectric layer


38


(1 mm thick) in which a radial waveguide is formed, a ground layer


37


, a dielectric layer


36


(0.2 mm thick), the phase control layer


35


, a dielectric layer


34


(0.2 mm thick), a ground layer


33


in which the coupling slot


21


is formed, a dielectric layer


32


(0.3 mm thick), the radiating element layer


31


, a dielectric layer


31


B (1 mm thick), and a passive element layer


31


A.




In this structure, the dielectric layer


34


between the phase control layer


35


and ground layer


33


has a space ensured by 0.2-mm thick spacers


34


A, and switches


17


S are formed at once on the phase control layer


35


.




In this case, the spacer


34


A may be arranged below the coupling slot


21


. With this arrangement, a space immediately under the coupling slot


21


, which generally an unused region, also serves as a region in which the spacer


34


A is arranged, thereby reducing the area occupied by the spacer


34


A.




In addition, if a material having high relative dielectric constant of about 5 to 30 such as alumina is used as the spacer


34


A, the coupling slots


21


and the strip lines


16


on the phase control layer


35


are efficiently coupled in a high-frequency manner.




As shown in FIG.


13


(


c


), the phase control layer


35


has a two-layered structure in which an insulating layer


35


C is formed on the dielectric layer


36


. The control signal lines


53


are separately wired on the layers


35


A and


35


B to connect the driver units


12


and the phase shift circuits


17


A to


17


D, respectively.




Assume that the following conditions are given:






the number of radiating elements (row×column): 72×72 elements








wiring line width/wiring line interval (L/S): 4/4 μm






In this case, when ½ phase shifters


17


on each row are controlled by the same driving unit


12


, and control signal lines


58


equal in number to the layers


35


A and


35


B are to be formed, the width of the wiring bundle of the control signal lines


53


is given by:






8 μm×36 elements×4 bits/2 layers=0.58 mm






If the wiring line bundle has the width of around 0.58 mm, this wiring line bundle can be formed, within the region having 5 mm square, together with the 4-bit phase shifter coping with an RF signal having 30 GHz. For this reason, the interval between the radiating elements


15


can be set to 5 mm, thereby realizing the high-frequency (30 GHz) high-gain (36 dBi) phased array antenna without decreasing a beam scanning range.




Example 2 of the present invention will be described below with reference to FIG.


14


.





FIG. 14

shows views of a circuit arrangement of Example 2, in which FIG.


14


(


a


) is a diagram showing a circuit arrangement in a phase shifter formation region, FIG.


14


(


b


) is a schematic view showing a multilayered structure, and FIG.


14


(


c


) is an enlarged view showing the arrangement of a control line layer portion


53


A in a phase control layer


35


.




In this example, as a spacer forming a dielectric layer


34


, a spacer


34


B made of a conductor is used in place of a spacer


34


A having high dielectric constant.




In this case, the conductive spacer


34


B is arranged at a position of a via hole (connection hole)


36


A formed on the dielectric layer


36


, in which ground patterns, e.g., ground patterns of a coupling layer


37


and a coupling layer


33


are electrically connected to each other.




With this structure, an inter-ground-plate unnecessary mode (a parallel-plate mode) can be suppressed without individually forming any means which couples ground potentials with each other.




Example 3 of the present invention will be described below with reference to FIG.


15


.





FIG. 15

shows views of a circuit arrangement of Example 3, in which FIG.


15


(


a


) is a diagram showing a circuit arrangement in a phase shifter formation region, FIG.


15


(


b


) is a schematic view showing a multilayered structure, and FIG.


15


(


c


) is an enlarged view showing the arrangement of a control line layer portion


53


A in a phase control layer


35


.




In this structure, as shown in FIG.


12


(


a


), a space serving as a mounting space for switches


17


S is ensured by a dielectric film


34


B.




In particular, a dielectric layer


34


is made up of only a dielectric film


34


C in FIG.


12


(


a


). In Example 3, a substrate


34


D is inserted between the dielectric film


34


C and a coupling layer


33


.




When the necessary distance between the phase control layer


35


and the coupling layer


33


is considerably larger than the height of the switch


17


S, a dielectric layer


34


portion above the height of the space for receiving the switch


17


S is constructed by the substrate


34


D.




Assuming that, for example, the dielectric layer


34


needs a thickness of 0.2 mm, and the switch


17




s


has the height of about 7 μm as described above. In this case, the dielectric layer


34


C (e.g., a polyimide film) may have a thickness of about 10 μm, and the remaining height of 0.19 mm is compensated by the substrate


34


D.




With this structure, the dielectric film


34


C is suppressed thin, thereby easily forming the dielectric film


34


C.




A dielectric (e.g., relative dielectric constant=5 to 30) is used as the substrate


34


D so that an RF signal from a strip line


16


on the phase control layer


35


is efficiently coupled with a radiating element


15


via a coupling slot


21


.




Example 4 of the present invention will be described below with reference to FIG.


16


.





FIG. 16

shows views of a circuit arrangement of Example 4, in which FIG.


16


(


a


) is a diagram showing a circuit arrangement in a phase shifter formation region, FIG.


16


(


b


) is a schematic view showing a multilayered structure, and FIG.


16


(


c


) is an enlarged view showing the arrangement of a control line layer portion


53


A in a phase control layer


35


.




In Example 4, as shown in FIG.


12


(


b


), a space


34


S serving as a mounting space for switches


17


S is ensured by the thickness of the wiring pattern of the phase control layer


35


.




In this structure, a wiring pattern


16


B which is a part of a strip line


16


is formed by plating it thick to have a thickness larger than the height of the switch


17


S.




A substrate


34


D is inserted between the thick-film wiring pattern


16


B and a coupling layer


33


.




A material having a high dielectric constant (e.g., relative dielectric constant=5 to 30) is used as the substrate


34


D so that an RF signal from the strip line


16


of the phase control layer


35


is efficiently coupled with a radiating element


15


via a coupling slot


21


.




Example 5 of the present invention will be described below with reference to FIG.


17


.





FIG. 17

shows views of a circuit arrangement of Example 5, in which FIG.


17


(


a


) is a diagram showing a circuit arrangement in a phase shifter formation region, FIG.


17


(


b


) is a schematic view showing a multilayered structure, and FIG.


17


(


c


) is an enlarged view showing the arrangement of a control line layer portion


53


A in a phase control layer


35


.




In Example 5, as shown in FIG.


12


(


c


), a space


34


S serving as a mounting space for switches


17


S is ensured by a substrate


34


E having a cavity


34


F.




In this structure, the cavity (space)


34


F is formed at the position, in the substrate


34


E, where the switch


17


S is mounted on the phase control layer


35


, and the switch


17


S is housed in the cavity


34


F when the substrates are tightly bonded.




A material having a high dielectric constant (e.g., relative dielectric constant=5 to 30) is used as the substrate


34


E so that an RF signal from a strip line


16


of the phase control layer


35


is efficiently coupled with a radiating element


15


via a coupling slot


21


.




As a method of forming the cavity


34


F in the substrate


34


E, machining in which the surface of the substrate


34


E is cut using a router or in which a through hole is formed by punching may be used.




Alternatively, after a photosensitive resin is applied on an organic substrate, the resin corresponding to the cavity


34


F may be removed by exposing and developing processes. Various types of the formation methods are usable.




Examples 1 to 5 have exemplified the case wherein the space


34


S serving as a space in which the switch


17




s


is mounted is formed above the phase control layer


35


. As in FIG.


11


(


b


), however, the space


34


S may be formed below the phase control layer


35


.




As described above, the case wherein a radial waveguide is adopted as a distribution/synthesis unit


14


is described with reference to

FIGS. 13

to


17


. However, the form shown in

FIG. 4

, i.e., a distribution/synthesis layer


39


using the branch strip line may also be used.




In addition, as described above, the present invention can also be applied to a stacking order different from that in the examples in

FIGS. 13

to


17


. For example, the multilayered structure is obtained by sequentially stacking from the bottom to top, a phase control layer


35


, dielectric layer


36


, coupling layer


37


, dielectric layer


38


A, distribution/synthesis layer


39


, dielectric layer


38


, coupling layer


33


, dielectric layer


32


, and radiating element layer


31


, and the distribution/synthesis layer


39


and the phase control layer


35


can also be arranged as innermost and outermost layers, respectively.




In this case, as a means for coupling RF signals between the layers in this structure, for example, a feed pin extending through a hole formed in the dielectric layer


37


may connect the phase control layer


35


to the distribution/synthesis layer


39


in a high-frequency manner, and a feed pin extending along the coupling layer


37


and coupling layer


33


may also connect the phase control layer


35


to a radiating element


15


.




In this manner, the phase control layer


35


is arranged as the outermost layer so that the stacked structure can be obtained regardless of the height of a phase shifter


17


.




In addition, as the form shown in

FIG. 6

, the radiation feeder


27


and the multilayered substrate unit


2


may be separately formed to use a space-fed system. By using this system, a layer functioning as the distribution/synthesis unit


14


(the distribution/synthesis layer


27


shown in

FIG. 2

or the radial waveguide in Examples shown in

FIGS. 13

to


17


) can be excluded from the multilayered substrate unit


2


.




INDUSTRIAL APPLICABILITY




The phased array antenna of the present invention is a high-gain antenna applicable to an RF band, and is effective for a satellite tracking on-vehicle antenna or satellite borne antenna used for satellite communication.



Claims
  • 1. A phased array antenna used to transmit/receive an RF signal such as a microwave and milliwave to adjust a beam direction by controlling a phase of the RF signal transmitted/received by each radiation element, characterized by comprisinga first multilayered structure made up of at least radiation element means on which a large number of radiation elements are arranged, and phase control means on which a large number of phase controllers for controlling the phase of the RF signal transmitted/received to/from each radiation element are mounted, wherein each phase controller includes a plurality of driver means for outputting control signals to give a predetermined phase shift amount for each radiating element and a plurality of phase shift means for receiving the control signals to control a phase of each radiating element, the phase shift means being simultaneously formed on a substrate of the phase control means, and the phase control means has an internal space having a predetermined height on an internal layer surface mounted with the phase controllers.
  • 2. A phased array antenna according to claim 1, characterized in that said phased array antenna has a first coupling layer arranged between the phase control means and the radiating element means to couple the RF signals.
  • 3. A phased array antenna used to transmit/receive an RF signal such as a microwave and milliwave to adjust a beam direction by controlling a phase of the RF signal transmitted/received by each radiation element, characterized by comprisinga first multilayered structure in which phase control means on which each phase controller for controlling the phase of the RF signal transmitted/received to/from each radiating element is mounted, a first coupling layer for coupling the RF signals, radiating element means on which a large number of radiating elements are arranged, and a passive element layer are sequentially stacked, wherein each phase controller includes a plurality of driver means for outputting control signals to give a predetermined phase shift amount for each radiating element and a plurality of phase shift means for receiving the control signals to control a phase of each radiating element, the phase shift means being simultaneously formed on a substrate of the phase control means, and the phase control means has an internal space having a predetermined height on an internal layer surface mounted with the phase controllers.
  • 4. A phased array antenna according to claim 1, characterized in that the phase control means has a second multilayered structure having a plurality of wiring layers.
  • 5. A phased array antenna according to claim 3, characterized in that each dielectric layer is formed between the respective layers constructing said first multilayered structure.
  • 6. A phased array antenna according to claim 1, characterized in that said phased array antenna further comprises a distribution/synthesis unit for distributing a transmission signal to each phase controller and synthesizing a reception signal from each phase controller.
  • 7. A phased array antenna according to claim 1, characterized in that each phase shift means comprises a plurality of phase shift circuits for receiving outputs from the driver means and capable of making strip lines, each having a length corresponding to a different phase shift amount, switch by using RF switches.
  • 8. A phased array antenna according to claim 1, characterized in that each driver means comprises a data distributor for receiving control data from a control unit to distribute the control data for predetermined radiating elements, and a plurality of phase controllers for latching and outputting outputs from the data distributor as the control signals on the basis of a trigger signal.
  • 9. A phased array antenna according to claim 8, characterized in that the trigger signal is a pulse signal.
  • 10. A phased array antenna according to claim 8, characterized in that the trigger signal is always output to the phase controller.
  • 11. A phased array antenna according to claim 1, characterized in that the driver means uses a flip chip.
  • 12. A phased array antenna according to claim 7, characterized in that the RF switch is comprised of a micromachine switch for electrically connecting/releasing a strip line to/from another strip line through a contact supported apart from the strip line by electrically or magnetically operating the contact.
  • 13. A phased array antenna according to claim 1, characterized in that the radiating element is a patch or slot antenna.
  • 14. A phased array antenna according to claim 6, characterized in that said distribution/synthesis unit is comprised of a distribution/synthesis layer having a branch circuit using a strip line or a radial waveguide using a metal enclosure with an internal space, and the distribution/synthesis layer is coupled to the phase control means via a second coupling layer.
  • 15. A phased array antenna according to claim 6, characterized in that the distribution/synthesis unit is comprised of a primary radiation unit for performing space feeding.
  • 16. A phased array antenna according to claim 2, characterized in that the first coupling layer couples layers by using a coupling slot or conductive feed pin.
  • 17. A phased array antenna according to claim 14, characterized in that the second coupling layer couples layers by using a coupling slot or conductive feed pin.
  • 18. A phased array antenna according to claim 5, characterized in that the dielectric layer is made of glass.
  • 19. A phased array antenna according to claim 12, characterized in that the predetermined height is made larger than a maximum height of the contact from a bottom surface of the micromachine switch.
  • 20. A phased array antenna according to claim 1, characterized in that the predetermined height is ensured by a dielectric spacer formed on the phase control means.
  • 21. A phased array antenna according to claim 20, characterized in that said phased array antenna comprises a first coupling layer arranged between the phase control means and the radiating element means to couple the RF signals, and the dielectric spacer is formed below a coupling slot of the first coupling layer.
  • 22. A phased array antenna according to claim 1, characterized in that the predetermined height is ensured by a conductive spacer formed on the phase control means.
  • 23. A phased array antenna according to claim 10, characterized in that the predetermined height is ensured by a sacrificial layer used to form the micromachine switch and a dielectric film formed on the sacrificial layer.
  • 24. A phased array antenna according to claim 19, characterized in that the predetermined height is ensured by forming thick a wiring pattern conductor except for a portion brought into contact with a contact of the micromachine switch.
  • 25. A phased array antenna according to claim 1, characterized in that the predetermined height is ensured by a cavity formed by partially removing a dielectric layer formed on the phase control means.
  • 26. A phased array antenna according to claim 1, characterized in that the driver means are arranged on two sides of the phase control means.
  • 27. A method of manufacturing a phased array antenna used to transmit/receive an RF signal such as a microwave and milliwave to adjust a beam direction by controlling a phase of the RF signal transmitted/received by each radiation element, characterized by comprising the step of:patterning, by photolithography and etching, at least radiating element means on which a large number of radiation elements are arranged and phase control means on which parts of phase controllers for controlling the phase of the RF signal transmitted/received to/from each radiation element are simultaneously formed, respectively; stacking the patterned layers in a predetermined order; and bonding the stacked layers to each other.
  • 28. A method of manufacturing a phased array antenna according to claim 27, characterized in that each phase controller includes a plurality of driver means for outputting control signals to give a predetermined phase shift amount for each radiating element and a plurality of phase shift means for receiving the control signals to control a phase shift of each radiating element.
  • 29. A method of manufacturing a phased array antenna according to claim 28, characterized in that the driver means include a plurality of flip chips, and each phase shift means comprises a plurality of phase shift circuits for receiving outputs from the driver means and capable of making strip lines, each having a length corresponding to a different phase shift amount, switch by using RF switches.
  • 30. A method of manufacturing a phased array antenna according to claim 29, characterized in that the RF switch is comprised of a micromachine switch for electrically connecting/releasing a strip line to/from another strip line through a contact supported apart from the strip line by electrically or magnetically operating the contact.
  • 31. A method of manufacturing a phased array antenna according to claim 27, characterized in that the phase control means has the step of forming the strip lines of the micromachine switch and an electrode formed below the contact,the step of selectively growing an electrolytic-plating portion on the strip line, the step of forming a sacrificial layer, and the step of forming the contact on the sacrificial layer.
  • 32. A method of manufacturing a phased array antenna according to claim 31, characterized in that the sacrificial layer is made of polyimide.
  • 33. A method of manufacturing a phased array antenna according to claim 31, characterized in that the substrate is glass.
Priority Claims (1)
Number Date Country Kind
10-368067 Dec 1998 JP
PCT Information
Filing Document Filing Date Country Kind
PCT/JP99/06514 WO 00
Publishing Document Publishing Date Country Kind
WO00/39891 7/6/2000 WO A
US Referenced Citations (9)
Number Name Date Kind
4166274 Reudink et al. Aug 1979 A
4851855 Tsukamoto et al. Jul 1989 A
4904831 Nathanson et al. Feb 1990 A
4939527 Lamberty et al. Jul 1990 A
5623270 Kempkes et al. Apr 1997 A
6028552 Shuguang Feb 2000 A
6232920 Brookner et al. May 2001 B1
6246370 Wixforth Jun 2001 B1
6396440 Chen May 2002 B1
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Number Date Country
2241375 Dec 1998 CA
53097752 Aug 1978 JP
1-290301 Nov 1989 JP
5-91016 Dec 1993 JP
6-267926 Sep 1994 JP
11-74717 Mar 1999 JP