1. Field
The present invention is related to phased-array antennas and, more particularly, to low-cost active-array antennas for use with high-frequency communication systems.
2. Related Art
Phased array antennas (“PAA”) are installed on various mobile platforms (such as, for example, aircraft and land and sea vehicles) and provide these platforms with the ability to transmit and receive information via line-of-sight or beyond line-of-sight communications.
A PAA, also known as a phased antenna array, is a type of antenna that includes a plurality of sub-antennas (generally known as antenna elements, array elements, or radiating elements of the combined antenna) in which the relative amplitudes and phases of the respective signals feeding the array elements may be varied in a way that the effect on the total radiation pattern of the PAA is reinforced in desired directions and suppressed in undesired directions. In other words, a beam may be generated that may be pointed in or steered into different directions. Beam pointing in a transmit or receive PAA is achieved by controlling the amplitude and phase of the transmitted or received signal from each antenna element in the PAA.
The individual radiated signals are combined to form the constructive and destructive interference patterns produced by the PAA that result in one or more antenna beams. The PAA may then be used to point the beam, or beams, rapidly in azimuth and elevation.
Unfortunately, PAA systems are usually large and complex depending on the intended use of the PAA systems. Additionally, because of the complexity and power handling of known transmit and receive (“T/R”) modules, many times PAA systems are designed with separate transmit modules and receive modules with corresponding separate PAA apertures. This further adds to the problems relating to cost and size of the PAA system. As such, for some applications, the amount of room for the different components of the PAA system may be limited and these designs may be too large to fit within the space that may be allocated for the PAA system.
In addition to producing one or more antenna beams, the PAA also produces these one or more antenna beams with a predetermined polarization that is determined by the design of the PAA. The polarization of the PAA is intrinsic and is a property of the radiated signals that are the radiated waves produced by the PAA. These radiated waves oscillate with a given orientation where the polarization of the PAA refers to the orientation of the electric field (i.e., the E-plane) of the radiated waves projected onto an imaginary plane perpendicular to the direction of motion of the radiated waves. Since most PAA are two-dimensional arrays, they typically produce elliptical polarization and generally the elliptical polarization is designed to simplify to circular polarization. This circular polarization may be “right-hand” circular polarization (“RHCP”) or “left-hand” circular polarization (“LHCP”), where a PAA that transmits and/or receives RHCP signals cannot receive LHCP signals and, likewise, a PAA that transmits and/or receives LHCP signals cannot receive RHCP signals because both these situations describe cross-polarized signals situations. The terms left-hand and right-hand are designated based on utilizing the “thumb in the direction of the propagation” rule that is well known to those of ordinary skill in the art.
In order to operate with both RHCP and LHCP, many PAA systems are designed as polarization switchable PAA systems that may switch operation from RHCP to LHCP and wise-versa. A problem with these polarization switchable PAA systems is that they are typically complex and expensive and not well suited for more cost conscious uses. As such, at present, there are many situations where non-switchable PAA systems with fixed circular polarization (either RHCP or LHCP) are designed and used. Unfortunately, once a PAA system is designed with a fixed circular polarization, it is very difficult and costly to redesign that particular PAA system design to operate with the opposite fixed circular polarization because typically the change in the polarization design of the PAA system will require a redesign, requalification, and remanufacturing of the integrated circuit chipset, which will have a significant impact on the cost and production schedule of producing the new PAA system. This is a problem if the particular PAA system has been designed for a particular custom use and/or for a particular vehicle where a change of polarization is desired (either for a new mission, use, or upgrade) and other useable PAA system designs are not readily available.
Therefore, there is a need for an apparatus that overcomes the problems described above.
Disclosed is a switchable transmit and receive phased array antenna (“STRPAA”). The STRPAA includes a housing, a plurality of radiating elements, and a plurality of transmit and receive (“T/R”) modules. The STRPAA may also include either a first multilayer printed wiring board (“MLPWB”) configured to produce a first elliptical polarization or a second MLPWB configured to produce a second elliptical polarization within the housing.
The first MLPWB includes a first MLPWB top surface and a first MLPWB bottom surface and the second MLPWB includes a second MLPWB top surface and a second MLPWB bottom surface. The plurality of radiating elements may be attached to either the first MLPWB top surface or the second MLPWB top surface. If attached to the first MLPWB top surface, the plurality of radiating elements are attached to the first MLPWB top surface at a predetermined azimuth position while, if attached to the second MLPWB top surface, the plurality of radiating elements are attached to the second MLPWB top surface at approximately 180 degrees in azimuth from the predetermined azimuth position. The plurality of T/R modules may be attached to either the first MLPWB bottom surface or the second MLPWB bottom surface, where the plurality of T/R modules are in signal communication with either the first MLPWB bottom surface or the second MLPWB bottom surface. Each T/R module of the plurality of T/R modules may be located on either the first MLPWB bottom surface opposite a corresponding radiating element of the plurality of radiating elements attached to the first MLPWB top surface or the second MLPWB bottom surface opposite the corresponding radiating element of the plurality of radiating elements attached to the second MLPWB top surface, where each T/R module is in signal communication with the corresponding radiating element located opposite the T/R module.
The STRPAA may be fabricated utilizing a method that includes inserting into the housing either the first MLPWB to configure the STRAA to produce the first elliptical polarization or the second MLPWB to configure the STRAA to produce the second elliptical polarization. The plurality of radiating elements are then attached either to a first MLPWB top surface of the first MLPWB if the first MLPWB is inserted in the housing or a second MLPWB top surface of the second MLPWB if the second MLPWB is inserted in the housing. The plurality of radiating elements may then be attached to the first MLPWB top surface at a predetermined azimuth position or the plurality of radiating elements are attached to the second MLPWB top surface after first rotating each element of the plurality of radiating elements, by approximately 180 degrees in azimuth, from the predetermined azimuth position, prior to attaching the plurality of radiating elements to the second MLPWB top surface. The plurality of T/R modules may then be attached to a first MLPWB bottom surface of the first MLPWB if the first MLPWB is inserted in the housing or to a second MLPWB bottom surface of the second MLPWB if the second MLPWB is inserted in the housing.
If already deployed in the field, the STRPAA may be converted to operate from a first elliptical polarization to a second elliptical polarization utilizing a conversion process. The process may include first detaching the radiating elements and T/R modules from the first MLPWB and removing the first MLPWB from the housing, where the MLPWB is configured to produce the first elliptical polarization. The process then includes inserting the second MLPWB into the housing, where the second MLPWB is configured to produce the second elliptical polarization. Moreover, the process includes attaching the detached radiating elements to the second MLPWB top surface of the second MLPWB and attaching the detached T/R modules to the second MLPWB bottom surface of the second MLPWB.
Other devices, apparatus, systems, methods, features and advantages of the disclosure will be or will become apparent to one with skill in the art upon examination of the following figures and detailed description. It is intended that all such additional systems, methods, features and advantages be included within this description, be within the scope of the disclosure, and be protected by the accompanying claims.
The disclosure may be better understood by referring to the following figures. The components in the figures are not necessarily to scale, emphasis instead being placed upon illustrating the principles of the disclosure. In the figures, like reference numerals designate corresponding parts throughout the different views.
A switchable transmit and receive phased array antenna (“STRPAA”) is disclosed. The STRPAA includes a housing, a plurality of radiating elements, and a plurality of transmit and receive (“T/R”) modules. The STRPAA may also include either a first multilayer printed wiring board (“MLPWB”) configured to produce a first elliptical polarization or a second MLPWB configured to produce a second elliptical polarization within the housing.
The first MLPWB includes a first MLPWB top surface and a first MLPWB bottom surface and the second MLPWB includes a second MLPWB top surface and a second MLPWB bottom surface. The plurality of radiating elements may be attached to either the first MLPWB top surface or the second MLPWB top surface. If attached to the first MLPWB top surface, the plurality of radiating elements are attached to the first MLPWB top surface at a predetermined azimuth position while, if attached to the second MLPWB top surface, the plurality of radiating elements are attached to the second MLPWB top surface at approximately 180 degrees in azimuth from the predetermined azimuth position. The plurality of T/R modules may be attached to either the first MLPWB bottom surface or the second MLPWB bottom surface, where the plurality of T/R modules are in signal communication with either the first MLPWB bottom surface or the second MLPWB bottom surface. Each T/R module of the plurality of T/R modules may be located on either the first MLPWB bottom surface opposite a corresponding radiating element of the plurality of radiating elements attached to the first MLPWB top surface or the second MLPWB bottom surface opposite the corresponding radiating element of the plurality of radiating elements attached to the second MLPWB top surface, where each T/R module is in signal communication with the corresponding radiating element located opposite the T/R module.
The STRPAA may be fabricated utilizing a method that includes inserting into the housing either the first MLPWB to configure the STRAA to produce the first elliptical polarization or the second MLPWB to configure the STRAA to produce the second elliptical polarization. The plurality of radiating elements are then attached either to a first MLPWB top surface of the first MLPWB if the first MLPWB is inserted in the housing or a second MLPWB top surface of the second MLPWB if the second MLPWB is inserted in the housing. The plurality of radiating elements may then be attached to the first MLPWB top surface at a predetermined azimuth position or the plurality of radiating elements are attached to the second MLPWB top surface after first rotating each element of the plurality of radiating elements, by approximately 180 degrees in azimuth, from the predetermined azimuth position, prior to attaching the plurality of radiating elements to the second MLPWB top surface. The plurality of T/R modules may then be attached to a first MLPWB bottom surface of the first MLPWB if the first MLPWB is inserted in the housing or to a second MLPWB bottom surface of the second MLPWB if the second MLPWB is inserted in the housing.
If already deployed in the field, the STRPAA may be converted to operate from a first elliptical polarization to a second elliptical polarization utilizing a conversion process. The process may include first detaching the radiating elements and T/R modules from the first MLPWB and removing the first MLPWB from the housing, where the MLPWB is configured to produce the first elliptical polarization. The process then includes inserting the second MLPWB into the housing, where the second MLPWB is configured to produce the second elliptical polarization. Moreover, the process includes attaching the detached radiating elements to the second MLPWB top surface of the second MLPWB and attaching the detached T/R modules to the second MLPWB bottom surface of the second MLPWB.
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In this example, the STRPAA 102 is a phased array antenna (“PAA”) that includes a plurality of T/R modules with corresponding radiation elements that in combination are capable of transmitting 122 and receiving 124 signals through the STRPAA 102. In this example, the STRPAA 102 may be configured to operate within a K-band frequency range (i.e., about 20 GHz to 40 GHz for NATO K-band and 18 GHz to 26.5 GHz for IEEE K-band).
The power supply 108 is a device, component, and/or module that provides power to the other units (i.e., STRPAA 102, controller 104, and temperature control system 106) in the antenna system 100. Additionally, the controller 104 is a device, component, and/or module that controls the operation of the antennas system 100. The controller 104 may be a processor, microprocessor, microcontroller, digital signal processor (“DSP”), or other type of device that may either be programmed in hardware and/or software. The controller 104 may control the array pointing angle of the STRPAA 102, polarization, tapper, and general operation of the STRPAA 102.
The temperature control system 106 is a device, component, and/or module that is capable of controlling the temperature on the STRPAA 102. In an example of operation, when the STRPAA 102 heats up to a point when it needs some type of cooling, it may indicate this need to either the controller 104, temperature control system 106, or both. This indication may be the result of a temperature sensor within the STRPAA 102 that measures the operating temperature of the STRPAA 102. Once the indication of a need for cooling is received by either the temperature control system 106 or controller 104, the temperature control system 106 may provide the STRPAA 102 with the needed cooling via, for example, air or liquid cooling. In a similar way, the temperature control system 106 may also control the temperature of the power supply 108.
It is appreciated by those skilled in the art that the circuits, components, modules, and/or devices of, or associated with, the antenna system 100 are described as being in signal communication with each other, where signal communication refers to any type of communication and/or connection between the circuits, components, modules, and/or devices that allows a circuit, component, module, and/or device to pass and/or receive signals and/or information from another circuit, component, module, and/or device. The communication and/or connection may be along any signal path between the circuits, components, modules, and/or devices that allows signals and/or information to pass from one circuit, component, module, and/or device to another and includes wireless or wired signal paths. The signal paths may be physical, such as, for example, conductive wires, electromagnetic wave guides, cables, attached and/or electromagnetic or mechanically coupled terminals, semi-conductive or dielectric materials or devices, or other similar physical connections or couplings. Additionally, signal paths may be non-physical such as free-space (in the case of electromagnetic propagation) or information paths through digital components where communication information is passed from one circuit, component, module, and/or device to another in varying digital formats without passing through a direct electromagnetic connection.
In
The honeycomb aperture plate 204 may be a metallic or dielectric structural plate that includes a plurality of channels 220, 222, and 224 through the honeycomb aperture plate 204 where the plurality of channels define the honeycomb structure along the honeycomb aperture plate 204. The WAIM sheet 220 is then attached to the top or outer surface of the honeycomb aperture plate 204. In general, the WAIM sheet 220 is a sheet of non-conductive material that includes a plurality of layers that have been selected and arranged to minimize the return loss and to optimize the impedance match between the STRPAA 102 and free space so as to allow improved scanning performance of the STRPAA 102.
The MLPWB 206 (also known as multilayer printed circuit board) is a printed wiring board (“PWB”) (also known as a printed circuit board—“PCB”) that includes multiple trace layers inside the PWB. In general, it is a stack up of multiple PWBs that may include etched circuitry on both sides of each individual PWB where lamination may be utilized to place the multiple PWBs together. The resulting MLPWB allows for much higher component density than on a signal PWB.
In this example, the MLPWB 206 has two surfaces a top 226 surface (i.e., a MLPWB top surface) and a bottom surface 228 (i.e., a MLPWB bottom surface) having etched electrical traces on each surface 226 and 228. The plurality of T/R modules 214, 216, and 218 may be attached to the bottom surface 228 of the MLPWB 206 and the plurality of radiating elements 208, 210, and 212 may be attached to the top surface 226 of the MLPWB 206. In this example, the plurality of T/R modules 214, 216, and 218, may be in signal communication with the bottom surface 228 of the MLPWB 206 via a plurality of conductive electrical interconnects 230, 232, 234, 236, 238, 240, 242, 244, and 246, respectively.
In one embodiment, the electrical interconnects may be embodied as “fuzz Buttons®”. It is appreciated to those of ordinary skill in the art that in general, a “fuzz Button®” is a high performance “signal contact” that is typically fashioned from a single strand of gold-plated beryllium-copper wire formed into a specific diameter of dense cylindrical material, ranging from a few tenths of a millimeter to a millimeter. They are often utilized in semiconductor test sockets and PWB interconnects where low-distortion transmission lines are a necessity. In another embodiment, the electrical interconnects may be implemented by solder utilizing a ball grid array of solder balls that may be reflowed to form the permanent contacts.
The radiating elements 208, 210, and 212 may be separate modules, devices, and/or components that are attached to the top surface 226 of the MLPWB 206 or they may actually be part of the MLPWB 206 as etched elements on the surface of the top surface 226 of the MLPWB 206 (such as, for example, a microstrip/patch antenna element). In the case of separate modules, the radiating elements 208, 210, 212 may be attached to the top surface 226 of the MLPWB 206 utilizing the same techniques as utilized in attaching the plurality of T/R modules 214, 216, and 218 on the bottom surface 228 of the MLPWB 206 including the use of electrical interconnects (not shown).
In either case, the plurality of radiating elements 208, 210, and 212 are in signal communication with the plurality of T/R modules 214, 216, and 218 through a plurality of conductive channels (herein referred to as “via” or “vias”) 248, 250, 252, 254, 256, and 258 through the MLPWB 206, respectively. In this example, each radiating element 208, 210, and 212 is in signal communication with a corresponding individual T/R module 214, 216, and 218 that is located on the opposite surface of the MLPWB 206. Additionally, each radiating element 208, 210, and 212 will correspond to an individual channel 220, 222, and 224. The vias 248, 250, 252, 254, 256, and 258 may include conductive metallic and/or dielectric material. In operation, the radiating elements may transmit and/or receive wireless signals such as, for example, K-band signals.
It is appreciated by those of ordinary skill in the art that the term “via” or “vias” is well known. Specifically, a via is an electrical connection between layers in a physical electronic circuit that goes through the plane of one or more adjacent layers, in this example the MLPWB 206 being the physical electronic circuit. Physically, the via is a small conductive hole in an insulating layer that allows a conductive connection between the different layers in MLPWB 206. In this example, the vias 248, 250, 252, 254, 256, and 258 are shown as individual vias that extend from the bottom surface 228 of the MLPWB 206 to the top surface 226 of the MLPWB 206, however, each individual via may actually be a combined via that includes multiple sub-vias that individually connect the individual multiple layers of the MLPWB 206 together.
The MLPWB 206 may also include a radio frequency (“RF”) distribution network (not shown) within the layers of the MLPWB 206. The RF distribution network may be a corporate feed network that uses signal paths to distribute the RF signals to the individual T/R modules of the plurality of T/R modules. As an example, the RF distribution network may include a plurality of stripline elements and Wilkinson power combiners/dividers.
It is appreciated by those of ordinary skill in the art that for the purposes of simplicity in illustration only three radiating elements 208, 210, 212 and three T/R modules 214, 216, and 218 are shown. Furthermore, only three channels 220, 222, and 224 are shown. However, it is appreciated that there may be many more radiating elements, T/R modules, and channels than what is specifically shown in
Additionally, it is also appreciated that only two vias 248, 250, 252, 254, 256, and 258 are shown per pair combination of the radiating elements 208, 210, and 212 and the T/R modules 214, 216, and 218. In this example, the first via per combination pair may correspond to a signal path for a first polarization signal and the second via per combination pair may correspond to a signal path for a second polarization signal. However, it is appreciated that there may additional vias per combination pair.
In this example, referring back to the honeycomb aperture plate 204, the channels 220, 222, and 224 act as waveguides for the corresponding radiating elements 208, 210, and 212. As such, the channels 220, 222, and 224 may be air, gas, or dielectric filled.
The pressure plate 202 may be a part of the housing 200 that includes inner surface 260 that butts up to the bottom of the plurality of T/R modules 214, 216, and 218 and pushes them against the bottom surface 228 of the MLPWB 206. The pressure plate 202 may also include a plurality of compression springs (not shown) along the inner surface 260 that apply additional force against the bottoms of the T/R modules 214, 216, and 218 to push them against the bottom surface 228 of the MLPWB 206.
In
The bonding layer 306 provides mechanical bonding as well as electrical properties to electrically connect via 307 and via 308 to each other and via 309 and 310 to each other. As an example, the bonding layer 306 may be made from a bonding material, such as bonding materials provided by Ormet Circuits, Inc.® of San Diego, Calif., for example, FR-408HR. The thickness of the bonding layer 306 may be, for example, approximately 4 thousandth of an inch (“mils”).
In this example, the first PWB sub-assembly 302 may include nine (9) substrates 311, 312, 313, 314, 315, 316, 317, 318, and 319. Additionally, ten (10) metallic layers (for example, copper) 320, 321, 322, 323, 324, 325, 326, 327, 328, and 329 insolate the nine substrates 311, 312, 313, 314, 315, 316, 317, 318, and 319 from each other. Similarly, the second PWB sub-assembly 304 may also include nine (9) substrates 330, 331, 332, 333, 334, 335, 336, 337, and 338. Additionally, ten (10) metallic layers (for example, copper) 339, 340, 341, 342, 343, 344, 345, 346, 347, and 348 insolate the nine substrates 330, 331, 332, 333, 334, 335, 336, 337, and 338 from each other. In this example, the bonding layer 306 bounds metallic layer 320 to metallic layer 348.
In this example, similar to the example described in
In this example, the diameters of vias 307 and 308 and vias 309 and 310 may be reduced as opposed to having a single pair of vias penetrate the entire MLPWB 300 as has been done in conventional architectures. In this manner, the size of the designs and architectures on MLPWB 300 may be reduced in size to fit more circuitry with respect to radiating elements (such as radiating element 350). As such, in this approach, the MLPWB 300 may allow more and/or smaller radiating elements to be placed on top surface 351 of the MLPWB 300.
For example, as stated previously, radiating element 350 may be formed on or within the top surface 351 of the MLPWB 300. The T/R module 352 may be mounted on the bottom surface 353 of the MLPWB 300 utilizing electrical interconnect signal contacts. In this manner, the radiating element 350 may be located opposite of the corresponding T/R module 352 in a manner that does not require a 90-degree angle or bend in the signal path connecting the T/R module 352 to the radiating element 350. More specifically, the radiating element 350 may be substantially aligned with the T/R module 352 such that the vias 307, 308, 309, and 310 form a straight line path between the radiating element 350 and the T/R module.
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In this example, a radiating element 434 is shown formed in the MLPWB 400 at substrate layer 406, which may be embodied as a printed antenna. The radiation element 434 is shown to have two radiators 436 and 438, which may be etched into layer 406. As an example, the first radiator 436 may radiate a first type of polarization (such as, for example, vertical polarization or right-hand circular polarization) and the second radiator 438 may radiate a second type of polarization (such as, for example, horizontal polarization or left-hand circular polarization) that is orthogonal to the first polarization. The radiating element 434 may also include grounding, reflecting, and/or isolation elements 440 to improve the directivity and/or reduce the mutual coupling of the radiating element. The first radiator 436 may be fed by a first probe 442 that is in signal communication with the contact pad 426, through a first via 444, which is in signal communication with the T/R module 412 through the electrical interconnect signal contact 418. Similarly, the second radiator 438 may be fed by a second probe 446 that is in signal communication with the contact pad 428, through a second via 448, which is in signal communication with the T/R module 412 through the electrical interconnect signal contact 420. In this example, the first via 444 may be part of, or all of, the first probe 442 based on how the architecture of the radiating element 434 is designed in substrate layer 406. Similarly, the second via 448 may also be part of, or all of, the second probe 446. The first and second probes 442 and 446 are generally feeds points for the first and second radiators 436 and 438.
In this example, a RF distribution network 450 is shown. An RF connector 452 is also shown in signal communication with the RF distribution network 450 via contact pad 454 on the bottom surface 414 of the MLPWB 400. As discussed earlier, the RF distribution network 450 may be a stripline distribution network that includes a plurality of power combiner and/or dividers (such as, for example, Wilkinson power combiners) and stripline terminations. The RF distribution network 450 is configured to feed a plurality of T/R modules attached to the bottom surface 414 of the MLPWB 400. In this example, the RF connector 452 may be a SMP-style miniature push-on connector such as, for example, a G3PO® type connector produced by Corning Gilbert Inc.® of Glendale, Ariz. or other equivalent high-frequency connectors, where the port impedance is approximately 50 ohms.
In this example, a honeycomb aperture plate 454 is also shown placed adjacent to the top surface 456 of the MLPWB 400. The honeycomb aperture plate 454 is a partial view of the honeycomb aperture plate 204 shown in
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Only three (3) metallic layers 510, 512, and 514 are shown around substrates 504 and 506. Additionally, the bonding layer is not shown. A T/R module 516 is shown attached to the bottom surface 518 of the MLPWB 500 through the holder 520 that includes a plurality of electrical interconnect signal contacts 522, 524, 526, and 528. The electrical interconnect signal contacts 522, 524, 526, and 528 may be in signal communication with a plurality of formed and/or etched contact pads 530, 532, 534, and 536, respectively, on the bottom surface 518 of the MLPWB 500.
In this example, the radiating element 538 is shown formed in the MLPWB 500 at substrate layer 508 such as a microstrip antenna which may be etched into layer 508. Similar to
Similar to the example in
In this example, a honeycomb aperture plate 560 is also shown placed adjacent to the top surface 562 of the MLPWB 500. Again, the honeycomb aperture plate 560 is a partial view of the honeycomb aperture plate 204 shown in
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The T/R module 904 may include two power switching integrated circuits (“ICs”) 914 and 916 and a beam processing IC 918. The switching ICs 914 and 916 and beam processing IC 918 may be monolithic microwave integrated circuits (‘MMICs”) and they may be placed in signal communication with each other utilizing “flip-chip” packaging techniques.
It is appreciated by those of ordinary skill in the art that in general, flip-chip packaging techniques are a method for interconnecting semiconductor devices, such as integrated circuits “chips” and microelectromechanical systems (“MEMS”) to external circuitry utilizing solder bumps or gold stud bumps that have been deposited onto the chip pads (i.e., chip contacts). In general, the bumps are deposited on the chip pads on the top side of a wafer during the final wafer processing step. In order to mount the chip to external circuitry (e.g., a circuit board or another chip or wafer), it is flipped over so that its top side faces down, and aligned so that its pads align with matching pads on the external circuit, and then either the solder is reflowed or the stud bump is thermally compressed to complete the interconnect. This is in contrast to wire bonding, in which the chip is mounted upright and wires are used to interconnect the chip pads to external circuitry.
In this example, the T/R module 904 may include circuitry that enables the T/R module 904 to have a switchable transmission signal path and reception signal path. The T/R module 904 may include a first, second, third, and fourth transmission path switches 920, 922, 924, and 926, a first and second 1:2 splitters 928 and 930, a first and second low pass filters (“LPFs”) 932 and 934, a first and second high pass filters (“HPFs”) 936 and 938, a first, second, third, fourth, fifth, sixth, and seventh amplifiers 940, 942, 944, 946, 948, 950, and 952, a phase-shifter 954, and attenuator 956.
In this example, the first and second transmission path switches 920 and 922 may be in signal communication with the RF distribution network 912, of the MLPWB 902, via signal path 958. Additionally, the third and fourth transmission path switches 924 and 926 may be in signal communication with the radiating element 906, of the MLPWB 902, via signal paths 960 and 962 respectively.
Furthermore, the third transmission path switch 924 and fourth amplifier 946 may be part of the first power switching MMIC 914 and the fourth transmission path switch 926 and fifth amplifier 948 may be part of the second power switching MMIC 916. Since the first and second power switching MMICs 914 and 916 are power providing ICs, they may be fabricated utilizing gallium-arsenide (“GaAs”) technologies. The remaining first and second transmission path switches 920 and 922, first and second 1:2 splitters 928 and 930, first and second LPFs 932 and 934, first and second HPFs 936 and 938, first, second, third, sixth, and seventh amplifiers 940, 942, 944, 950, and 952, phase-shifter 954, and attenuator 956 may be part of the beam processing MMIC 918. The beam processing MMIC 918 may be fabricated utilizing silicon-germanium (“SiGe”) technologies. In this example, the high frequency performance and the high density of the circuit functions of SiGe technology allows for a footprint of the circuit functions of the T/R module to be implemented in a phase array antenna that has a planar tile configuration (i.e., generally, the planar module circuit layout footprint is constrained by the radiator spacing due to the operating frequency and minimum antenna beam scan requirement).
In
In the receive (also known as reception) mode, the T/R module 904 receives a first polarization received signal 1014 from the first radiator in the radiating element 906 and a second polarization received signal 1016 from the second radiator in the radiating element 906.
In the receive mode, the first, second, third, and fourth transmission path switches 920, 922, 924, and 926 are set to pass the first polarization received signal 1014 and second polarization received signal 1016 to the RF distribution network 912 through the variable attenuator 956, phase-shifter 954, and first amplifier 940. Specifically, the first polarization received signal 1014 is passed through the third transmission path switch 924 to the sixth amplifier 950. The resulting amplified first polarization received signal 1018 is then passed through the second LPF 934 to the second 1:2 splitter 930 resulting in a filtered first polarization received signal 1020.
Similarly, the second polarization received signal 1016 is passed through the fourth transmission path switch 926 to the seventh amplifier 952. The resulting amplified second polarization received signal 1022 is then passed through the second LPF 934 to the second 1:2 splitter 930 resulting in a filtered second polarization received signal 1024. The second 1:2 splitter 930 then acts as a 2:1 combiner and combines the filtered first polarization received signal 1020 and filtered second polarization received signal 1024 to produce a combined received signal 1026 that is passed through the second transmission path switch 922, variable attenuator 956, phase-shifter 954, first amplifier 940, and the first transmission path switch 920 to produce a combined received signal 1028 that is passed to the RF distribution network 912 via signal path 1002.
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In this example, the spacers 1516 and 158 are conductive sheets (i.e., such as metal) with patterned bumps to provide grounding connections between the MLWPB 1514 ground planes and the adjacent metal plates (i.e., pressure plate 1502 and honeycomb aperture plate 1506, respectively). Specifically, spacer 1516 maintains an RF ground between the MLPWB 1514 and the Pressure Plate 1502. Spacer 1518 maintains an RF ground between the MLPWB 1514 and the Honeycomb Aperture Plate 1506. The shape and cutout pattern of the spacers 1516 and 1518 also maintains RF isolation between the individual array elements to prevent performance degradation that might occur without this RF grounding and isolation. In general, the spacers 1516 and 1518 maintain the grounding and isolation by absorbing any flatness irregularities present between the chassis components (for example pressure plate 1502 and honeycomb aperture plate 1506) and the MLPWB 1514. This capability may be further enhanced by utilizing micro bumps in the surface of a plurality of shims (i.e., the spacers 1516 and 1518) that can collapse by varying degrees when compressed to absorb flatness irregularities.
In
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In
It is appreciated by those of ordinary skill in the art that similar to the MLPWB for the housing of the STRPAA, the T/R module ceramic package 1810 may include multiple layers of substrate and metal forming microcircuits that allow signals to pass from the T/R module contacts 1814 to T/R module top surface contacts (not shown) on the top surface 1710 of the T/R module 1700. As an example, the T/R module ceramic package 1810 may include ten (10) layers of ceramic substrate and eleven (11) layers of metallic material (such as, for example, aluminum nitride (“AlN”) substrate with gold metallization) with substrate thickness of approximately 0.005 inches with multiple vias.
In
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The fourth conductive metallic pad 2006 may be an RF communication port. The fourth conductive metallic pad 2006 may be an RF common port, which is the input RF port for the T/R module 1700 module in the transmit mode and the output RF port for the T/R module 1700 in the receive mode. Turning back to
Additionally, in this example, port 2008 provides +5V biasing voltage for the GaAs power amplifier in the power switching MMICs 1802 and 1804, ports 2010 and 2016 provide −5V basing voltage for the SiGe beam processing MMIC 1806, and the GaAs power switching MMIC 1802 and 1804. Port 2012 provides a digital data signal and port 2018 provides the digital clock signal, both these signals are for phase shifters in SiGe beam processing MMIC 1806 and form part of the array beam steering control. Moreover, port 2014 provides +3.3V biasing voltage for the SiGe MMIC 1806.
In this example, the T/R module ceramic package 1810 may include multiple layers of substrate and metal forming microcircuits that allow signals to pass from the T/R module contacts 1814 to T/R module top surface contacts (not shown) on the top surface 1710 of the T/R module 1700.
Turning to
In
Turning to
It is appreciated by those of ordinary skill in the art that the STRPAA has been described as having a fixed plurality of radiating elements that may be either separate modules, devices, and/or components that are attached to the top surface 226 of the MLPWB 206 or they may actually be part of the MLPWB 206 as etched elements on the surface of the top surface 226 of the MLPWB 206 (such as, for example, a microstrip/patch antenna element) as was described in
In this example, a first and second elliptical polarizations will be described as either “right-hand” circular polarization (“RHCP”) or “left-hand” circular polarization (“LHCP”) since these are the two types of polarization available for circular polarized signals. In this disclosure, the terms left-hand and right-hand are designated based on utilizing the “thumb in the direction of the propagation” rule that is well known to those of ordinary skill in the art.
An advantage of the design of the STRPAA is that it allows the STRPAA to be fabricated to operate in either fixed RHCP or fixed LHCP utilizing the same common radiating elements and T/R modules. The only needed change in the fabrication process is to change the type of MLPWB that is utilized, the azimuth orientation of the radiating elements, and possibly the housing. This is an important advantage because it eliminates the cost of redesigning the T/R modules and fabricating another set of modified T/R modules for the fabrication process. Additionally, another advantage is that if the STRPAA has already been produced and is operating in the field, this disclosure describes a relatively simple modification process that may be performed in the field that allows the existing STRPAA to be converted from operating in one elliptical polarization to another elliptical polarization. In this example modification process, the STRPAA will utilize the same common radiating elements and T/R modules and again the only needed change in the process is to change the type of MLPWB that is utilized, the azimuth orientation of the radiating elements, and possibly the housing. In this example modification process, the first MLPWB utilized by the STRPAA (that operates a first type of elliptical polarization) may be removed from the STRPAA and replaced with a new MLPWB that is configured to operate with a second type of elliptical polarization. In general, this means that the fabrication process allows the fabrication of STRPAAs that are configured to operate in either fixed RHCP or fixed LHCP. Moreover, the conversion process allows a STRPAA in the field that was fabricated to operate with either fixed RHCP or fixed LHCP may be modified in the field (or sent back to be quickly modified away from the field) to operate in the opposite polarization (i.e., RHCP to LHCP or LHCP to RHCP).
For the purpose of describing how the STRPAA may be either configured in fabrication with one of two types of elliptical polarizations or converted from a first type of elliptical polarization to another type of elliptical polarization, the STRPAA (as describe earlier) may generally be described as including the housing, a plurality of radiating elements, and a plurality of T/R modules. However, unlike the previous examples, in this example, the STRPAA may also include either a first MLPWB configured to produce a first elliptical polarization or a second MLPWB configured to produce a second elliptical polarization within the housing. As before, the first MLPWB includes a first MLPWB top surface and a first MLPWB bottom surface and the second MLPWB also includes a second MLPWB top surface and a second MLPWB bottom surface.
The plurality of radiating elements may be attached to either the first MLPWB top surface or the second MLPWB top surface. If attached to the first MLPWB top surface, the plurality of radiating elements are attached to the first MLPWB top surface at a predetermined azimuth position while, if attached to the second MLPWB top surface, the plurality of radiating elements are attached to the second MLPWB top surface at approximately 180 degrees in azimuth from the predetermined azimuth position. In other words, the predetermined azimuth position is the position that the radiators are oriented within the honeycomb aperture plate and/or on the top surface of the MLPWB that is determined by the design parameters of the STRPAA utilizing the first MLPWB. In relation to this orientation (i.e., the predetermined azimuth position), the radiators attached to the second MLPWB will be oriented in a “mirrored” position which corresponds to rotating each individual radiator by approximately 180 degrees from the orientation of the radiators attached to the first MLPWB.
Also as described earlier, the plurality of T/R modules may be attached to either the first MLPWB bottom surface or the second MLPWB bottom surface, where the plurality of T/R modules are in signal communication with either the first MLPWB bottom surface or the second MLPWB bottom surface. Each T/R module of the plurality of T/R modules may be located on either the first MLPWB bottom surface opposite a corresponding radiating element of the plurality of radiating elements attached to the first MLPWB top surface or the second MLPWB bottom surface opposite the corresponding radiating element of the plurality of radiating elements attached to the second MLPWB top surface, where each T/R module is in signal communication with the corresponding radiating element located opposite the T/R module.
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Therefore, if a new housing is needed, the process changes the housing and continues to step 2408 where the first MLPWB is inserted into the second housing. The plurality of radiating elements are then attached to the first MLPWB in step 2410. In this example, plurality of radiating elements are attached to the first MLPWB with an initial orientation (i.e., the predetermined azimuth position or angle) that is determined by the design of the STRPAA. The plurality of T/R modules are then also attached to the first MLPWB in step 2412. In this example, the plurality of radiating elements are attached to the first MLPWB front surface and the plurality of T/R modules are attached to the first MLPWB bottom surface, where the positions of the plurality of radiator feed points to the rotated plurality of radiating elements does not change with the second housing from the original location of the plurality of radiator feed points of the non-rotated radiator elements on the previous MLPWB top surface. The process then closes the second housing and the process ends 2414.
If, instead, a new housing in not needed or is not desirable, the process instead goes to step 2416. Example situations where the new housing is not desirable include situations where rotating the plurality of radiating elements causes a shift in the plurality of channels in the honeycomb aperture plate that causes a sizing issue because the mirror rotation of the individual radiating elements cause a shift in the position of radiating element that is mirrored about the radiating feed point of the radiating element (will be discussed in relation to
The plurality of radiating elements are then attached to the first MLPWB in step 2418. Again, in this example, plurality of radiating elements are attached to the first MLPWB with an initial orientation that is determined by the design of the STRPAA. The plurality of T/R modules are then also attached to the first MLPWB in step 2420. In this example, the plurality of radiating elements are attached to the first MLPWB front surface and the plurality of T/R modules are attached to the first MLPWB bottom surface, where the positions of the plurality of radiator feed points to the rotated plurality of radiating elements does not change with the second housing from the original location of the plurality of radiator feed points of the non-rotated radiator elements on the previous MLPWB top surface. The process then closes the second housing and the process ends 2414.
If, instead, the STRPAA is to be configured to utilize LHCP, the process then determines if a previous run of the process (not shown) utilized a first housing and if the first housing needs to be changed for a second housing, step 2422. Again, as an example, if the previous run of the process produced a STRPAA configured to operate utilizing RHCP, the process determines if on top of changing the MLPWB, if the housing also has to change because the resulting mirrored radiating elements are now in a position along the new MLPWB that is different than the original positions of the radiating elements along the previous MLPWB for the reasons described earlier.
Therefore, if a new housing is needed, the process changes the housing and continues to step 2424 where the second MLPWB is inserted into the second housing. The plurality of radiating elements are then attached to the second MLPWB in step 2426. In this example, plurality of radiating elements are attached to the second MLPWB with an orientation that is approximately 180 from the original orientation (i.e., the predetermined azimuth position or angle) that is determined by the design of the STRPAA. The plurality of T/R modules are then also attached to the second MLPWB in step 2428. In this example, the plurality of radiating elements are attached to the second MLPWB front surface and the plurality of T/R modules are attached to the second MLPWB bottom surface, where the positions of the plurality of radiator feed points to the rotated plurality of radiating elements does not change with the second housing from the original location of the plurality of radiator feed points of the non-rotated radiator elements on the previous MLPWB top surface. The process then closes the second housing and the process ends 2414.
If, instead, a new housing in not needed or is not desirable, the process instead goes to step 2430. As discussed previously, example situations where the new housing is not desirable include situations where rotating the plurality of radiating elements causes a shift in the plurality of channels in the honeycomb aperture plate that causes a sizing issue because the mirror rotation of the individual radiating elements. In this example, the process maintains the use of a housing that is configured as the previous housing and inserts the second MLPWB into the first housing in step. Similar to before, in this example, the second MLPWB includes an added radiator feed line length that is added to the feed probes from the second MLPWB to the individual radiating elements. Again, this added radiator feed line length adds line length to the feed probes so as to feed the rotated radiating elements that are now in the same position as the original radiating elements but rotated about 180 degrees (i.e., flipped) but that now have radiator feed points that have been resulting shifted to the other side of the corresponding channel within the honeycomb aperture plate. As such, the added radiator feed line length is the needed line length to feed the radiating element from the feed probe from the first MLPWB.
The plurality of radiating elements are then attached to the second MLPWB in step 2432. Again, in this example, the plurality of radiating elements are attached to the second MLPWB with an initial orientation that is determined by the design of the STRPAA. The plurality of T/R modules are then also attached to the second MLPWB in step 2434. In this example, the plurality of radiating elements are attached to the second MLPWB front surface and the plurality of T/R modules are attached to the second MLPWB bottom surface, where the positions of the plurality of radiator feed points to the rotated plurality of radiating elements does not change with the first housing from the original location of the plurality of radiator feed points of the non-rotated radiator elements on the previous MLPWB top surface. The process then closes the second housing and the process ends 2414.
In this example, inserting the first MLPWB into the housing (in steps 2408 and 2416) includes inserting the first MLPWB into a first housing that has a first honeycomb aperture plate that is configured to produce the first elliptical polarization. As described earlier, the first housing includes a first pressure plate and the first honeycomb aperture plate has a plurality of channels. The first pressure plate is configured to push the plurality of T/R modules against the first MLPWB bottom surface and the plurality of radiating elements are configured to be placed approximately against the first honeycomb aperture plate. Each radiating element of the plurality of radiating elements is located at a corresponding channel of the plurality of channels of the first honeycomb aperture.
Similarly, inserting the second MLPWB into the housing includes inserting the second MLPWB into a second housing that has a second honeycomb aperture plate that is configured to produce the first elliptical polarization.
The second housing includes a second pressure plate and the second honeycomb aperture plate having a plurality of channels. The second pressure plate is configured to push the plurality of T/R modules against the second MLPWB bottom surface and the plurality of radiating elements are configured to be placed approximately against the second honeycomb aperture plate. Each radiating element of the plurality of radiating elements is located at a corresponding channel of the plurality of channels of the second honeycomb aperture.
In this example, the second housing is separate from the first housing and the plurality of channels in the second honeycomb aperture are shifted to a new position with relation to an original position of the plurality of chancel in the first honeycomb aperture. The new position of the plurality of channels in the second honeycomb aperture is located such that a plurality of radiator feed points to the rotated plurality of radiating elements does not change with the second housing from a location of the plurality of radiator feed points to the originally attached and non-rotated radiator elements in the first housing.
Additionally, in this example, attaching the radiating elements to the first MLPWB top surface of the first MLPWB includes placing the plurality of rotated radiating elements approximately against the first honeycomb aperture plate and attaching the T/R modules to the first MLPWB bottom surface of the first MLPWB includes pressing the plurality of T/R modules against the first MLPWB bottom surface.
In
If, instead, the original housing is changed for a new housing, the process proceeds to step 2518 where the second MLPWB is inserted into the new housing. The plurality of radiating elements are then attached to the second MLPWB, in step 2520, with the second orientation that is approximately 180 degrees in rotation from the original orientation of the plurality of radiating elements that were attached to the first MLPWB in the original housing. The plurality of T/R modules are then attached to the second MLPWB in step 2522, the new housing is closed, and the process ends 2516.
In this example, inserting the first MLPWB into the housing (in step 2510) includes inserting the second MLPWB into a first housing that has a first honeycomb aperture plate that is configured to produce the first elliptical polarization. As described earlier, the first housing includes a first pressure plate and the first honeycomb aperture plate has a plurality of channels. The first pressure plate is configured to push the plurality of T/R modules against the first MLPWB bottom surface and the plurality of radiating elements are configured to be placed approximately against the first honeycomb aperture plate. Each radiating element of the plurality of radiating elements is located at a corresponding channel of the plurality of channels of the first honeycomb aperture.
Similarly, inserting the second MLPWB into the second housing (step 2518) includes inserting the second MLPWB into a second housing that has a second honeycomb aperture plate that is configured to produce the first elliptical polarization.
The second housing includes a second pressure plate and the second honeycomb aperture plate having a plurality of channels. The second pressure plate is configured to push the plurality of T/R modules against the second MLPWB bottom surface and the plurality of radiating elements are configured to be placed approximately against the second honeycomb aperture plate. Each radiating element of the plurality of radiating elements is located at a corresponding channel of the plurality of channels of the second honeycomb aperture.
In this example, the second housing is separate from the first housing and the plurality of channels in the second honeycomb aperture are shifted to a new position with relation to an original position of the plurality of chancel in the first honeycomb aperture. The new position of the plurality of channels in the second honeycomb aperture is located such that a plurality of radiator feed points to the rotated plurality of radiating elements does not change with the second housing from a location of the plurality of radiator feed points to the originally attached and non-rotated radiator elements in the first housing.
Additionally, in this example, attaching the radiating elements to the first MLPWB top surface of the first MLPWB includes placing the plurality of rotated radiating elements approximately against the first honeycomb aperture plate and attaching the T/R modules to the first MLPWB bottom surface of the first MLPWB includes pressing the plurality of T/R modules against the first MLPWB bottom surface.
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As described earlier, in this example, the radiating element 2600 is formed and/or etched on the top surface of an MLPWB. As described in
In this example,
It will be understood that various aspects or details of the disclosure may be changed without departing from the scope of the disclosure. It is not exhaustive and does not limit the claimed disclosures to the precise form disclosed. Furthermore, the foregoing description is for the purpose of illustration only, and not for the purpose of limitation. Modifications and variations are possible in light of the above description or may be acquired from practicing the disclosure. The claims and their equivalents define the scope of the disclosure.
The present patent application is a continuation-in-part (“CIP”) application, claiming priority under 35 U.S.C. §119(a) and 35 U.S.C. §120, to U.S. patent application Ser. No. 14/568,660, filed on Dec. 12, 2014, titled “Switchable Transmit and Receive Phased Array Antenna,” which is hereby incorporated by reference in its entirety.
Number | Date | Country | |
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Parent | 14568660 | Dec 2014 | US |
Child | 15161110 | US |