The present application claims priority under 35 U.S.C. § 119 to Chinese Patent Application No. 201810780299.5 (Serial No. 2018071700656530), filed Jul. 17, 2018, the entire content of which is incorporated herein by reference.
The present disclosure relates to communications systems and, more particularly, to couplers suitable for use in communications systems.
Couplers are widely used in the radio communications industry. Couplers may, for example, have an input port, an output port and a coupled port. A coupler may be configured to pass a first portion of a radio frequency (“RF”) signal that is input at the input port to the output port while coupling a second portion of the RF signal to the coupled port.
A first aspect of this disclosure is to provide a microstrip coupler. The microstrip coupler may comprise: a main conductive line comprising a first main section and a second main section; a first auxiliary conductive line comprising a first auxiliary section and a first end portion, wherein the first auxiliary section is adjacent and spaced apart from the first main section and is configured to couple with the main conductive line to generate a first coupled signal; a second auxiliary conductive line comprising a second auxiliary section and a second end portion, wherein the second auxiliary section is adjacent and spaced apart from the second main section and is configured to couple with the main conductive line to generate a second coupled signal; a transmission module comprising a first inlet, a second inlet and an outlet, wherein the first inlet is coupled to the first end portion, the second inlet is coupled to the second end portion, and the transmission module is configured to combine the first coupled signal from the first end portion and the second coupled signal from the second end portion into an output signal of the microstrip coupler and to pass the output signal to the outlet; and a coupled port coupled to the outlet and used for outputting the output signal.
A second aspect of this disclosure is to provide a coupler. The coupler may comprise: an input port; an output port; a combining node; a coupled port that is coupled to the combining node; a main transmission line that couples the input port to the output port; a first coupling element that is configured to pass a first coupled signal to the combining node, the first coupled signal comprising a first portion of a signal that is input to the main transmission line at the input port that is coupled from the main transmission line by the first coupling element; and a second coupling element that is configured to pass a second coupled signal to the combining node, the second coupled signal comprising a second portion of the signal that is input to the main transmission line at the input port that is coupled from the main transmission line by the second coupling element; wherein the first coupling element is spaced apart from the second coupling element.
Note that, in some cases the same elements or elements having similar functions are denoted by the same reference numerals in different drawings, and description of such elements is not repeated. In some cases, similar reference numerals and letters are used to refer to similar elements, and thus once an element is defined in one figure, it need not be further discussed for following figures.
In order to facilitate understanding, the position, size, range, or the like of each structure illustrated in the drawings may not be drawn to scale. Thus, the disclosure is not necessarily limited to the position, size, range, or the like as disclosed in the drawings
The present invention will be described with reference to the accompanying drawings, which show a number of example embodiments thereof. It should be understood, however, that the present invention can be embodied in many different ways, and is not limited to the embodiments described below. Rather, the embodiments described below are intended to make the disclosure of the present invention more complete and fully convey the scope of the present invention to those skilled in the art. It should also be understood that the embodiments disclosed herein can be combined in any way to provide many additional embodiments.
The terminology used herein is for the purpose of describing particular embodiments, but is not intended to limit the scope of the present invention. All terms (including technical terms and scientific terms) used herein have meanings commonly understood by those skilled in the art unless otherwise defined. For the sake of brevity and/or clarity, well-known functions or structures may be not described in detail.
Herein, when an element is described as located “on” “attached” to, “connected” to, “coupled” to or “in contact with” another element, etc., the element can be directly located on, attached to, connected to, coupled to or in contact with the other element, or there may be one or more intervening elements present. In contrast, when an element is described as “directly” located “on”, “directly attached” to, “directly connected” to, “directly coupled” to or “in direct contact with” another element, there are no intervening elements present. In the description, references that a first element is arranged “adjacent” a second element can mean that the first element has a part that overlaps the second element or a part that is located above or below the second element.
Herein, the foregoing description may refer to elements or nodes or features being “connected” or “coupled” together. As used herein, unless expressly stated otherwise, “connected” means that one element/node/feature is electrically, mechanically, logically or otherwise directly joined to (or directly communicates with) another element/node/feature. Likewise, unless expressly stated otherwise, “coupled” means that one element/node/feature may be mechanically, electrically, logically or otherwise joined to another element/node/feature in either a direct or indirect manner to permit interaction even though the two features may not be directly connected. That is, “coupled” is intended to encompass both direct and indirect joining of elements or other features, including connection with one or more intervening elements.
Herein, terms such as “upper”, “lower”, “left”, “right”, “front”, “rear”, “high”, “low” may be used to describe the spatial relationship between different elements as they are shown in the drawings. It should be understood that in addition to orientations shown in the drawings, the above terms may also encompass different orientations of the device during use or operation. For example, when the device in the drawings is inverted, a first feature that was described as being “below” a second feature can be then described as being “above” the second feature. The device may be oriented otherwise (rotated 90 degrees or at other orientation), and the relative spatial relationship between the features will be correspondingly interpreted.
Herein, the term “A or B” used through the specification refers to “A and B” and “A or B” rather than meaning that A and B are exclusive, unless otherwise specified.
The term “exemplary”, as used herein, means “serving as an example, instance, or illustration”, rather than as a “model” that would be exactly duplicated. Any implementation described herein as exemplary is not necessarily to be construed as preferred or advantageous over other implementations. Furthermore, there is no intention to be bound by any expressed or implied theory presented in the detailed description.
Herein, the term “substantially”, is intended to encompass any slight variations due to design or manufacturing imperfections, device or component tolerances, environmental effects and/or other factors. The term “substantially” also allows for variation from a perfect or ideal case due to parasitic effects, noise, and other practical considerations that may be present in an actual implementation.
Herein, certain terminology, such as the terms “first”, “second” and the like, may also be used in the following description for the purpose of reference only, and thus are not intended to be limiting. For example, the terms “first”, “second” and other such numerical terms referring to structures or elements do not imply a sequence or order unless clearly indicated by the context.
Further, it should be noted that, the terms “comprise”, “include”, “have” and any other variants, as used herein, specify the presence of stated features, steps, operations, elements, and/or components, but do not preclude the presence or addition of one or more other features, steps, operations, elements, components, and/or groups thereof.
Referring to
The main conductive line 10 comprises a first main section 11, a second main section 12, and a conductor 112 that couples the first main section 11 to the second main section 12. A first end of the main conductive line 10 is coupled to the input port 60, and the second end is coupled to the output port 70. When an input signal is passed through the input port 60 to the main conductive line 10, a first portion of the energy of the input signal passes from the input port 60 to the output port 70, and a second portion of energy of the input signal passes to the coupled port 50.
The first auxiliary conductive line comprises a first auxiliary section 21, a first end portion 22 and a first isolated end portion 23. The first auxiliary section 21 may be adjacent and spaced apart from the first main section 11 so that the first auxiliary section 21 extends substantially in parallel with the first main section 11. The first auxiliary section 21 couples with the main conductive line 10 to generate a first coupled signal on the first auxiliary section 21. A first portion of the energy of the first coupled signal may pass to the first end portion 22 of the first auxiliary section 21, and a second portion of the energy of the first coupled signal may pass to the first isolated end portion 23 of the first auxiliary section 21. In some embodiments, the length of the first auxiliary section 21 of the first auxiliary conductive line may be λ/4, where λ refers to the wavelength corresponding to the center frequency of a signal propagating in the first auxiliary section 21. The coupler may be designed to operate on RF signals in a specific frequency band, and hence the signal propagating in the first auxiliary section 21 and in other portions of the coupler may be within the specific frequency band. The length of the first main section 11 of the main conductive line 10 that is adjacent the first auxiliary section 21 may also be λ/4. The first end portion 22 and the first isolated end portion 23 of the first auxiliary conductive line may extend gradually away from the main conductive line 10. In some embodiments, the first isolated end portion 23 may be grounded through a matched load (e.g., the matched load is 50 ohms for a 50-ohm system).
The second auxiliary conductive line comprises a second auxiliary section 31, a second end portion 32 and a second isolated end portion 33. The second auxiliary section 31 may be adjacent and spaced apart from the second main section 12 so that the second auxiliary section 31 extends substantially in parallel with the second main section 12. The second auxiliary section 31 couples with the main conductive line 10 to generate a second coupled signal on the second auxiliary section 31. A first portion of the energy of the second coupled signal may pass to the second end portion 32 of the second auxiliary section 31, and a second portion of the energy of the second coupled signal may pass to the second isolated end portion 33 of the second auxiliary section 31. In some embodiments, the length of the second auxiliary section 31 of the second auxiliary conductive line is λ/4, where λ is the wavelength corresponding to the center frequency of a signal propagating in the second auxiliary section 31. The length of the second main section 12 of the main conductive line 10 that is adjacent the second auxiliary section 31 may also be λ/4. The second end portion 32 and the second isolated end portion 33 of the second auxiliary conductive line may extend gradually away from the main conductive line 10. In some embodiments, the second isolated end portion 33 may be grounded through a matched load (e.g., the matched load is 50 ohms for a 50-ohm system).
The transmission module 40 comprises a first inlet 41, a second inlet 42 and an outlet 43. The first inlet 41 is coupled to the first end portion 22, the second inlet 42 is coupled to the second end portion 32, and the outlet 43 is coupled to the coupled port 50. The first auxiliary conductive line and the second auxiliary conductive line may be arranged such that the first end portion 22 and the second end portion 32 are located in the vicinity of the transmission module 40 so as to conveniently couple to the transmission module 40. Appropriate arrangement of the main conductive line 10 and the first and second auxiliary conductive lines may make the structure of the microstrip coupler more compact. The transmission module 40 is used for combining (e.g., adding) a first signal that is passed from the first end portion 22 with a second signal that is passed from the second end portion 32 into an output signal of the microstrip coupler and transmitting the output signal to the outlet 43, and then the output signal is output through the coupled port 50. As the output signal output through the coupled port 50 is a combination of the first signal and the second signal, the output signal of the microstrip coupler may have a magnitude that is higher than that of the first signal or the second signal by appropriately controlling the phase difference between the first signal and the second signal during the combination.
In some embodiments, as shown in
In some embodiments, the length of at least one of the first transmission line 410 and the second transmission line 420 may be configured such that at the combining node (region A in
In the example of
In some embodiments, as shown in
Referring to
The main conductive line 10 comprises a first main section 11, a second main section 12, and a third main section 13. Although not shown, those skilled in the art will appreciate that the microstrip coupler may also include a conductor similar to the conductor 112 in
The configurations of the first auxiliary conductive line and the second auxiliary conductive line are as described above with reference to
The third auxiliary conductive line comprises a third auxiliary section 51, a third end portion 52 and a third isolated end portion 53. The third auxiliary section 51 is adjacent and spaced apart from the third main section 13 so that the third auxiliary section 51 extends substantially in parallel with the third main section 13. The third auxiliary section 51 couples with the main conductive line 10 to generate a third coupled signal on the third auxiliary section 51. A first portion of the energy of the third coupled signal may pass to the third end portion 52 of the third auxiliary section 51, and a second portion of the energy of the third coupled signal may pass to the third isolated end portion 53 of the third auxiliary section 51. In some embodiments, the length of the third auxiliary section 51 of the third auxiliary conductive line may be λ/4, where λ refers to the wavelength corresponding to the center frequency of a signal propagating in the third auxiliary section 51. The length of the third main section 13 of the main conductive line 10 that is adjacent the third auxiliary section 51 may also be λ/4. The third end portion 52 and the third isolated end portion 53 of the third auxiliary conductive line may extend gradually away from the main conductive line 10. In some embodiments, the third isolated end portion 53 may be grounded through a matched load (e.g., the matched load is 50 ohms for a 50-ohm system).
The transmission module 40 may comprise at least a first inlet 41, a second inlet 42, a third inlet 44 and an outlet 43. The first inlet 41 is coupled to the first end portion 22, the second inlet 42 is coupled to the second end portion 32, the third inlet 44 is coupled to the third end portion 52, and the outlet 43 is coupled to the coupled port 50. In some embodiments, the first auxiliary conductive line, the second auxiliary conductive line and the third auxiliary conductive line may be arranged around the transmission module 40 so as to conveniently perform these couplings. Appropriate arrangement of the main conductive line 10 and the auxiliary conductive lines may make the structure of the microstrip coupler more compact. The transmission module 40 is used for combining (e.g., adding) at least the first coupled signal from the first end portion 22, the second coupled signal from the second end portion 32 and the third coupled signal from the third end portion 52 into an output signal of the microstrip coupler and transmitting the output signal to the outlet 43 The output signal is passed to the coupled port 50. As the output signal output through the coupled port 50 is a combination of at least the first signal, the second signal and the third signal, the output signal of the microstrip coupler may have a strength higher than that of the first signal, the second signal or the third signal by appropriately controlling the phase difference among the first signal, the second signal and the third signal during the combination.
As discussed above with reference to
As is further shown in
The main conductive line 10 comprises a first main section 11, a second main section 12, a third main section 13 and a fourth main section 14. Although not shown, those skilled in the art will appreciate that the microstrip coupler of the present disclosure according to these embodiments may also comprise a conductor similar to the conductor 112 in
The configurations of the first auxiliary conductive line and the second auxiliary conductive line are as described above with reference to
The fourth auxiliary conductive line comprises a fourth auxiliary section 61, a fourth end portion 62 and a fourth isolated end portion 63. The fourth auxiliary section 61 may be adjacent and spaced apart from the fourth main section 14 so that the fourth auxiliary section 61 extends substantially in parallel with the fourth main section 14. A portion of the energy of the input signal travelling along the main conductive line 10 couples to the fourth auxiliary section 61 to generate a fourth coupled signal. A first portion of the energy of the fourth coupled signal may pass to the fourth end portion 62 of the fourth auxiliary section 61, and a second portion of the energy of the fourth coupled signal may pass to the fourth isolated end portion 63 of the fourth auxiliary section 61. In some embodiments, the length of the fourth auxiliary section 61 of the fourth auxiliary conductive line may be λ/4, where λ refers to the wavelength corresponding to the center frequency of a signal propagating in the fourth auxiliary section 61. The length of the fourth main section 14 of the main conductive line 10 that runs adjacent to the fourth auxiliary section 61 may also be λ/4. The two ends of the fourth auxiliary section 61 may extend gradually away from the main conductive line 10, and an end of the fourth auxiliary section 61 is formed into the fourth end portion 62, and the other end is formed into the fourth isolated end portion 63. In some embodiments, the fourth isolated end portion 63 may be grounded through a matched load (e.g., the matched load is 50 ohms for a 50-ohm system).
The transmission module 40 comprises a first inlet 41, a second inlet 42, a third inlet 44, a fourth inlet 45 and an outlet 43. The first inlet 41 is coupled to the first end portion 22, the second inlet 42 is coupled to the second end portion 32, the third inlet 44 is coupled to the third end portion 52, the fourth inlet 45 is coupled to the fourth end portion 62, and the outlet 43 is coupled to the coupled port 50. The first auxiliary conductive line, the second auxiliary conductive line, the third auxiliary conductive line and the fourth auxiliary conductive line may be arranged around the transmission module 40 so as to conveniently perform these couplings. Appropriate arrangement of the main conductive line 10 and the auxiliary conductive lines may make the structure of the microstrip coupler more compact. The transmission module 40 is used for combining (e.g., adding) the first signal from the first end portion 22, the second signal from the second end portion 32, the third signal from the third end portion 52 and the fourth signal from the fourth end portion 62 into an output signal of the microstrip coupler signal and transmitting the output signal to the outlet 43, and then the output signal is output through the coupled port 50. As the output signal output through the coupled port 50 is a combination of the first signal, the second signal, the third signal and the fourth signal, the output signal of the microstrip coupler may achieve a strength higher than that of the first signal, the second signal, the third signal or the fourth signal by appropriately controlling the phase differences among the first signal, the second signal, the third signal and the fourth signal during the combination.
In some embodiments, although not shown in the drawings, those skilled in the art may appreciate that, in addition to the first, second, third and fourth transmission lines, the transmission module 40 may further comprise a fifth transmission line. An end portion of the fifth transmission line may be coupled to the fourth inlet 45, and the other end portion is coupled to an end portion 431 of the third transmission line as the other end of the first, second and fourth transmission lines, for example, in a region similar to the region A in
In addition, although not shown in the drawings, those skilled in the art may appreciate that the microstrip couplers according to embodiments of the present disclosure may further comprise an electrically isolated substrate and a conductive grounding member. The conductive grounding member is disposed on one surface of the electrically isolated substrate, and the main conductive line, the auxiliary conductive lines, and the transmission module are all disposed on the other surface of the electrically isolated substrate. By way of example, the microstrip couplers may be implemented on a printed circuit board that includes a dielectric substrate, and the various traces shown, for example, in
Note that, the component to which a reference sign in
The curve C1 represents a ratio (the unit of which is dB, hereinafter referred to as a parameter S21) of the signal power passed through the output port 70 of the microstrip coupler to the signal power input through the input port 60 as a function of frequency, the curve C2 represents a ratio (the unit of which is dB, hereinafter referred to as a parameter S31) of the signal power passed through the coupled port 50 to the signal power input through the input port 60 as a function of frequency, the curve C3 represents a ratio (the unit of which is dB, hereinafter referred to as a parameter S41) of the signal power passed through the first isolated end portion 23 to the signal power input through the input port 60 as a function of frequency, the curve C4 represents a ratio (the unit of which is dB, hereinafter referred to as a parameter S51) of the signal power passed through the second isolated end portion 33 to the signal power input through the input port 60 as a function of frequency, and a curve C5 represents a ratio (the unit of which is dB, i.e., return loss) of the signal power reflected back to the input port 60 to the signal power input through the input port 60 as a function of frequency. The points m1˜m7 in the figure are points taken on the curves C1˜C5, and the x-coordinate and y-coordinate of each point are also shown in
As can be seen from
As discussed above with respect to the microstrip coupler of
For example, referring again to
The first coupling element 13 and the second coupling element 14 are spaced apart from each other by the conductor 112. If, for example, a length of the first transmission line 410 is approximately equal to the sum of a length of the conductor 112 and a length of the second transmission line 420, then the first coupled signal and the second coupled signal may be substantially in-phase when those signals meet at the combining node (region A) in
One potential problem with conventional couplers is that they not only couple signal energy that is input at the input port of the coupler, but they also tend couple signal energy that is input at the output port of the coupler to the coupled port. The signal energy that is input at the output port of the coupler may comprise, for example, a reflected signal that is generated when a portion of a signal output from the coupler is reflected back towards the coupler by an imperfect impedance match downstream of the output port 70. If significant portions of such a reflected signal that is input to the coupler at output port 70 are coupled to the coupled port 50, this may, in some applications, have a negative impact on performance. The couplers according to embodiments of the present invention may be configured to reduce the amount of such a reflected signal that is passed to the coupled port 50.
When a reflected signal (or other signal) is input to the main conductive line 10 at output port 70, a first portion of this reflected signal will couple from the second main section 12 to the second auxiliary section 31 to generate a first coupled reflected signal on the second auxiliary section 31. Some of the energy of the first coupled reflected signal will pass to the isolated end portion 33 of the second auxiliary section 31, while the remainder of the energy of the first coupled reflected signal will pass through the end portion 32 of second auxiliary section 31 and over the second transmission line 420 to the combining node at region A. Similarly, a second portion of the reflected signal that is input to the main conductive line 10 at output port 70 will couple from the first main section 11 to the first auxiliary section 21 to generate a second coupled reflected signal on the first auxiliary section 21. Some of the energy of the second coupled reflected signal will pass to the isolated end portion 23 of the first auxiliary section 21, while the remainder of the energy of the second coupled reflected signal will pass through the end portion 22 of first auxiliary section 21 and over the first transmission line 410 to the combining node at region A.
If, for example, a length of the second transmission line 420 is shorter than the sum of a length of the conductor 112 and a length of the first transmission line 410 by λ/2, where λ is the wavelength corresponding to the center frequency of the reflected signal, then the first coupled reflected signal and the second coupled reflected signal may be substantially out-of-phase when those signals meet at the combining node (region A) in
Referring again to
While the example embodiments of the present invention discussed above are implemented as microstrip couplers, it will be appreciated that embodiments of the present invention are not limited thereto. For example, the couplers described above could also be implemented in stripline. As known to those of skill in the art, stripline is a transmission line medium that is similar to microstrip, but that includes a second dielectric substrate (or an air dielectric) that is disposed above the metal trace pattern and a second ground plane that is disposed on the second dielectric substrate opposite the metal trace pattern. Adding the second ground plane may reduce radiative loss from signals traversing the transmission lines as compared to microstrip.
Although some specific embodiments of the present invention have been described in detail with examples, it should be understood by a person skilled in the art that the above examples are only intended to be illustrative but not to limit the scope of the present invention. The embodiments disclosed herein can be combined arbitrarily with each other, without departing from the scope and spirit of the present invention. It should be understood by a person skilled in the art that the above embodiments can be modified without departing from the scope and spirit of the present invention. The scope of the present invention is defined by the attached claims.
Number | Date | Country | Kind |
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201810780299.5 | Jul 2018 | CN | national |