Fully Differential Coupler and Wideband Quadrature Generator

Abstract

The present invention discloses a fully differential coupler and a broadband quadrature generator. The fully differential coupler includes an input port, a through port, a coupling port, and an isolation port. The input port and the isolation port are located on one side of the fully differential coupler, and the through port and the coupling port are located on the other side of the fully differential coupler. The fully differential coupler of the present invention optimizes the port arrangement. The input port and the isolation port are on one side, and the through port and the coupling port are on the other side, which can achieve a smaller area and smaller trace loss in the layout implementation; the broadband quadrature generator formed by cascading multiple fully differential couplers significantly reduces the layout area and layout difficulty of the broadband quadrature generator.

Description

Technical Field

[0001] The present invention belongs to the field of communication technologies, and particularly relates to a fully differential coupler and a broadband quadrature generator. Background Art

[0002] Quadrature generators are widely used in modern radar and communication systems. A quadrature coupler is a commonly used passive quadrature generation circuit. In order to expand the operating bandwidth and reduce the quadrature error, a broadband quadrature generator based on coupler cascading is often adopted.

[0003] Refer Figure 1 Shown is the schematic diagram of a quadrature coupler in the prior art. This coupler mainly consists of the following parts, including a group of mutually coupled inductors L and a coupling capacitor C m , and parasitic capacitances C from the ports to the ground g . Its ports are respectively an input port IN (input port), a through port THRU (through port), a coupled port CPL (coupled port), and an isolation port ISO (isolation port), and all ports are matched. Each parameter is reasonably selected according to the impedance of the ports, so that the two output ports THRU and CPL output quadrature signals of 0° and 90° respectively.

[0004] Refer Figure 2 , Figure 3 Shown are respectively the schematic diagram and the layout diagram of a fully differential coupler in the prior art, including two groups of mutually coupled inductors L and a coupling capacitor C m , and parasitic capacitances C from the ports to the ground g . The ports include a first input port IN+ and a second input port IN-, a first through port THRU+ and a second through port THRU-, a first coupled port CPL+ and a second coupled port CPL-, a first isolation port ISO+ and a second isolation port ISO-. The first input port IN+ and the second input port IN-, and the first coupled port CPL+ and the second coupled port CPL- are located on one side of the fully differential coupler, and the first through port THRU+ and the second through port THRU-, and the first isolation port ISO+ and the second isolation port ISO- are located on the other side of the fully differential coupler.

[0005] Refer Figure 4 Shown is the layout diagram of a quadrature generator based on coupler cascading in the prior art, which is cascaded by 3 couplers t1. Through the mechanism of quadrature error cancellation, coupler cascading can achieve bandwidth expansion and reduce the quadrature signal error. However, since the through port THRU and the coupled port CPL are located on both sides of the coupler, the output routing path of the quadrature generator is complex, the layout area is large, and the layout difficulty is high.

[0006] Therefore, in view of the above technical problems, it is necessary to provide a fully differential coupler and a broadband quadrature generator. Summary of the Invention

[0007] In view of this, the object of the present invention is to provide a fully differential coupler and a broadband quadrature generator to optimize the port arrangement of the fully differential coupler.

[0008] In order to achieve the above object, the technical solution provided by an embodiment of the present invention is as follows:

[0009] A fully differential coupler includes an input port, a through port, a coupling port, and an isolation port. The input port and the isolation port are located on one side of the fully differential coupler, and the through port and the coupling port are located on the other side of the fully differential coupler.

[0010] In one embodiment, the fully differential coupler includes a first input port and a second input port, a first through port and a second through port, a first coupling port and a second coupling port, a first isolation port and a second isolation port. The first input port and the second input port, and the first isolation port and the second isolation port are located on one side of the fully differential coupler, and the first through port and the second through port, and the first coupling port and the second coupling port are located on the other side of the fully differential coupler.

[0011] In one embodiment, in the fully differential coupler:

[0012] A first inductor is provided between the first input port and the first node, and a third inductor is provided between the first through port and the first node;

[0013] A second inductor is provided between the second isolation port and the second node, and a fourth inductor is provided between the second coupling port and the second node;

[0014] A fifth inductor is provided between the second input port and the third node, and a seventh inductor is provided between the second through port and the third node;

[0015] A sixth inductor is provided between the first isolation port and the fourth node, and an eighth inductor is provided between the first coupling port and the fourth node;

[0016] Among them, the inductance values of the first inductor to the eighth inductor are all equal. The first inductor and the second inductor, the third inductor and the fourth inductor, the fifth inductor and the sixth inductor, and the seventh inductor and the eighth inductor are four groups of mutually coupled inductors respectively, and the coupling coefficients are equal.

[0017] In one embodiment, a coupling capacitor C is provided between the first node and the fourth node, and between the second node and the third node respectively m .

[0018] In one embodiment, a first parasitic capacitance C is respectively formed between the first input port, the second input port, the first through port, the second through port, the first coupling port, the second coupling port, the first isolation port, the second isolation port, the first node, the second node, the third node, the fourth node and the reference potential. g ;

[0019] A second parasitic capacitance C is respectively formed between the first input port and the second isolation port, between the first through port and the second coupling port, between the second input port and the first isolation port, between the second through port and the first coupling port, between the first node and the second node, and between the third node and the fourth node. f 。

[0020] In one embodiment, isolation resistors R are respectively provided between the first isolation port and the reference potential, and between the second isolation port and the reference potential. iso 。

[0021] In one embodiment, the first input port and the second input port respectively receive a first differential signal and a second differential signal, and the first through port, the second through port, the first coupling port, and the second coupling port respectively output a first output signal, a second output signal, a third output signal, and a fourth output signal. Moreover, the phase differences between the first output signal and the third output signal, between the third output signal and the second output signal, between the second output signal and the fourth output signal, and between the fourth output signal and the first output signal are all 90°.

[0022] The technical solution provided by an embodiment of the present invention is as follows:

[0023] A broadband quadrature generator, the broadband quadrature generator includes a first fully differential coupler and two second fully differential couplers. The second fully differential coupler is the above-mentioned fully differential coupler. The first fully differential coupler includes an input port, a through port, a coupling port, and an isolation port. The input port and the coupling port in the first fully differential coupler are located on one side of the first fully differential coupler, and the through port and the isolation port are located on the other side of the first fully differential coupler.

[0024] In one embodiment, the first fully differential coupler includes a first input port and a second input port, a first through port and a second through port, a first coupling port and a second coupling port, a first isolation port and a second isolation port. The first input port and the second input port, and the first coupling port and the second coupling port are located on one side of the fully differential coupler. The first through port and the second through port, and the first isolation port and the second isolation port are located on the other side of the fully differential coupler.

[0025] In one embodiment, the first input port and the second input port of the first fully differential coupler receive a first differential signal and a second differential signal respectively;

[0026] The first through port and the second through port of the first fully differential coupler are respectively connected to the first input port and the second input port of the first second fully differential coupler, and the first coupled port and the second coupled port of the first fully differential coupler are respectively connected to the first input port and the second input port of the second second fully differential coupler;

[0027] The first coupled port and the second coupled port of the first second fully differential coupler are respectively connected to the first coupled port and the second coupled port of the second second fully differential coupler, and output a first quadrature signal I±;

[0028] The first through port and the second through port of the first second fully differential coupler are respectively connected to the first through port and the second through port of the second second fully differential coupler, and output a second quadrature signal Q±.

[0029] The present invention has the following beneficial effects:

[0030] The fully differential coupler of the present invention optimizes the port arrangement. The input ports and the isolation ports are on one side, and the through ports and the coupled ports are on the other side, which can achieve a smaller area and smaller trace loss in the layout implementation;

[0031] The broadband quadrature generator composed of cascading multiple fully differential couplers significantly reduces the layout area and layout difficulty of the broadband quadrature generator. Description of the Drawings

[0032] In order to more clearly illustrate the technical solutions in the embodiments of the present application or the prior art, the following will briefly introduce the drawings required for use in the description of the embodiments or the prior art. Obviously, the drawings in the following description are only some embodiments recorded in the present application. For those of ordinary skill in the art, without creative efforts, other drawings can also be obtained based on these drawings.

[0033] Figure 1 It is a schematic diagram of an orthogonal coupler in the prior art;

[0034] Figure 2 It is a schematic diagram of a fully differential coupler in the prior art;

[0035] Figure 3 It is a layout schematic diagram of a fully differential coupler in the prior art;

[0036] Figure 4 It is a layout schematic diagram of an orthogonal generator based on coupler cascading in the prior art;

[0037] Figure 5 Schematic diagram of the fully differential coupler in the first embodiment of the present invention;

[0038] Figure 6 Layout schematic diagram of the fully differential coupler in the first embodiment of the present invention;

[0039] Figure 7 Layout schematic diagram of the broadband quadrature generator based on the fully differential coupler in the second embodiment of the present invention. Detailed implementation manners

[0040] In order to enable those skilled in the art to better understand the technical solutions in the present invention, the technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without making creative efforts shall fall within the protection scope of the present invention.

[0041] The present invention discloses a fully differential coupler, including an input port, a through port, a coupling port and an isolation port. The input port and the isolation port are located on one side of the fully differential coupler, and the through port and the coupling port are located on the other side of the fully differential coupler.

[0042] The present invention also discloses a broadband quadrature generator, which includes a first fully differential coupler and two second fully differential couplers, wherein:

[0043] The first fully differential coupler includes an input port, a through port, a coupling port and an isolation port, and the input port and the coupling port in the first fully differential coupler are located on one side of the first fully differential coupler, and the through port and the isolation port are located on the other side of the first fully differential coupler;

[0044] The first fully differential coupler includes an input port, a through port, a coupling port and an isolation port, and the input port and the isolation port in the second fully differential coupler are located on one side of the fully differential coupler, and the through port and the coupling port are located on the other side of the fully differential coupler.

[0045] The present invention will be further described below with specific embodiments.

[0046] Refer Figure 5 And Figure 6 As shown, the fully differential coupler in the first embodiment of the present invention includes an input port IN, a through port THRU, a coupling port CPL and an isolation port ISO. The input port IN and the isolation port ISO are located on one side of the fully differential coupler, and the through port THRU and the coupling port CPL are located on the other side of the fully differential coupler.

[0047] Specifically, the fully differential coupler includes a first input port IN+, a second input port IN-, a first through port THRU+, a second through port THRU-, a first coupled port CPL+, a second coupled port CPL-, a first isolation port ISO+, and a second isolation port ISO-. The first input port IN+ and the second input port IN-, and the first isolation port ISO+ and the second isolation port ISO- are located on one side of the fully differential coupler, and the first through port THRU+ and the second through port THRU-, and the first coupled port CPL+ and the second coupled port CPL- are located on the other side of the fully differential coupler.

[0048] In the fully differential coupler of this embodiment:

[0049] A first inductor is provided between the first input port IN+ and the first node A, and a third inductor is provided between the first through port THRU+ and the first node A;

[0050] A second inductor is provided between the second isolation port ISO- and the second node B, and a fourth inductor is provided between the second coupled port CPL- and the second node B;

[0051] A fifth inductor is provided between the second input port IN- and the third node C, and a seventh inductor is provided between the second through port THRU- and the third node C;

[0052] A sixth inductor is provided between the first isolation port ISO+ and the fourth node D, and an eighth inductor is provided between the first coupled port CPL+ and the fourth node D;

[0053] Among them, the inductance values of the first inductor to the eighth inductor are all equal (L / 2). The first inductor and the second inductor, the third inductor and the fourth inductor, the fifth inductor and the sixth inductor, and the seventh inductor and the eighth inductor are respectively four groups of mutually coupled inductors, and the coupling coefficients are equal, all being K.

[0054] Coupling capacitors C are respectively provided between the first node A and the fourth node D, and between the second node B and the third node C m .

[0055] First parasitic capacitors C are respectively formed between the first input port IN+, the second input port IN-, the first through port THRU+, the second through port THRU-, the first coupled port CPL+, the second coupled port CPL-, the first isolation port ISO+, the second isolation port ISO-, the first node A, the second node B, the third node C, the fourth node D and the reference potential g ;

[0056] A second parasitic capacitor C is formed between the first input port IN+ and the second isolation port ISO-, between the first through port THRU+ and the second coupling port CPL-, between the second input port IN- and the first isolation port ISO+, between the second through port THRU- and the first coupling port CPL+, between the first node A and the second node B, and between the third node C and the fourth node D. f .

[0057] Isolation resistors R are respectively arranged between the first isolation port ISO+ and the reference potential and between the second isolation port ISO- and the reference potential. iso .

[0058] In this embodiment, the first input port IN+ and the second input port IN- receive the first differential signal in+ and the second differential signal in- respectively, the first straight-through port THRU+, the second straight-through port THRU-, the first coupling port CPL+, and the second coupling port CPL- output the first output signal thru+, the second output signal thru-, the third output signal cpl+, and the fourth output signal cpl- respectively, and the phase difference between the first output signal thru+ and the third output signal cpl+, the third output signal cpl+ and the second output signal thru-, the second output signal thru- and the fourth output signal cpl-, and the fourth output signal cpl- and the first output signal thru+ is 90°.

[0059] Specifically, in this embodiment, in+ and in- are differential signals, and the phases of the first output signal thru+, the second output signal thru-, the third output signal cpl+, and the fourth output signal cpl- are 0°, 180°, 90°, and 270°, respectively.

[0060] Compared with the prior art, the CPL± port and ISO± port in this embodiment are exchanged, and a coupling capacitor C is added at the central node. m Capacitor C f , C g It is mainly realized by the parasitic capacitance of the transformer coil (inductance).

[0061] In the prior art, the ports (CPL and THRU) for outputting orthogonal signals are located on both sides of the coupler. In the coupler structure of this embodiment, the ports (CPL and THRU) for outputting orthogonal signals are located on the same side of the coupler, so a smaller area and smaller routing loss can be achieved in the layout implementation. In this circuit model, it is necessary to design the component values ​​so that the port reflection coefficients in odd and even modes are the same as those of the coupler in the prior art to achieve orthogonal output.

[0062] Ginseng Figure 7As shown in the figure, the broadband quadrature generator in the second embodiment of the present invention includes a first fully differential coupler t1 and two second fully differential couplers t2. The second fully differential coupler t2 is the fully differential coupler in the first embodiment, and the first fully differential coupler t1 is the fully differential coupler in the prior art. The first fully differential coupler t1 includes an input port, a through port, a coupling port, and an isolation port. The input port and the coupling port in the first fully differential coupler are located on one side of the first fully differential coupler, and the through port and the isolation port are located on the other side of the first fully differential coupler.

[0063] Specifically, referring Figure 2 、 Figure 3 As shown in the figure, the first fully differential coupler t1 includes a first input port IN+ and a second input port IN-, a first through port THRU+ and a second through port THRU-, a first coupling port CPL+ and a second coupling port CPL-, a first isolation port ISO+ and a second isolation port ISO-. The first input port IN+ and the second input port IN-, and the first coupling port CPL+ and the second coupling port CPL- are located on one side of the fully differential coupler, and the first through port THRU+ and the second through port THRU-, and the first isolation port ISO+ and the second isolation port ISO- are located on the other side of the fully differential coupler.

[0064] Isolation resistors R are respectively provided between the first isolation port ISO+ and the second isolation port ISO- and the reference potential iso ;

[0065] In the first fully differential coupler, a set of mutual coupling inductors (the inductance value of each inductor is L, and the coupling coefficient is K) are provided between the first input port IN+ and the first through port THRU+, and between the first coupling port CPL+ and the first isolation port ISO+. A set of mutual coupling inductors (the inductance value of each inductor is L, and the coupling coefficient is K) are provided between the second input port IN- and the second through port THRU-, and between the second coupling port CPL- and the second isolation port ISO-.

[0066] Coupling capacitors C are respectively provided between the first input port IN+ and the first coupling port CPL+, between the first through port THRU+ and the first isolation port ISO+, between the second input port IN- and the second coupling port CPL-, and between the second through port THRU- and the second isolation port ISO-. m ;

[0067] Parasitic capacitors C are respectively formed between the first input port IN+, the second input port IN-, the first through port THRU+, the second through port THRU+, the first coupling port CPL+, the second coupling port CPL+, the first isolation port ISO+, the second isolation port ISO- and the reference potentialg 。

[0068] In this embodiment, the first input port IN+ and the second input port IN- of the first fully differential coupler respectively receive the first differential signal in+ and the second differential signal in-, and the first through port THRU+, the second through port THRU-, the first coupling port CPL+, and the second coupling port CPL- respectively output the first output signal thru+, the second output signal thru-, the third output signal cpl+, and the fourth output signal cpl-. The phases of the first output signal thru+, the second output signal thru-, the third output signal cpl+, and the fourth output signal cpl- are 0°, 180°, 90°, and 270° respectively.

[0069] In this embodiment, one first fully differential coupler t1 and two second fully differential couplers t2 are as follows:

[0070] The first input port and the second input port of the first fully differential coupler t1 respectively receive the first differential signal and the second differential signal;

[0071] The first through port and the second through port of the first fully differential coupler t1 are respectively connected to the first input port and the second input port of the first second fully differential coupler t2, and the first coupling port and the second coupling port of the first fully differential coupler t1 are respectively connected to the first input port and the second input port of the second second fully differential coupler t2;

[0072] The first coupling port and the second coupling port of the first second fully differential coupler t2 are respectively connected to the first coupling port and the second coupling port of the second second fully differential coupler t2, and output the first quadrature signal I±;

[0073] The first through port and the second through port of the first second fully differential coupler t2 are respectively connected to the first through port and the second through port of the second second fully differential coupler t2, and output the second quadrature signal Q±.

[0074] It can be seen that cascading one first fully differential coupler t1 and two second fully differential couplers t2 in this embodiment can optimize the wiring strategy, significantly reduce the layout area and the layout difficulty.

[0075] From the above technical solutions, it can be seen that the present invention has the following advantages:

[0076] The fully differential coupler of the present invention optimizes the port arrangement. The input ports and the isolation ports are on one side, and the through ports and the coupling ports are on the other side, which can achieve a smaller area and smaller trace loss in the layout implementation;

[0077] A broadband quadrature generator composed of cascaded multiple fully differential couplers significantly reduces the layout area and layout difficulty of the broadband quadrature generator.

[0078] For those skilled in the art, it is obvious that the present invention is not limited to the details of the above-described exemplary embodiments, and the present invention can be implemented in other specific forms without departing from the spirit or basic characteristics of the present invention. Therefore, from any point of view, the embodiments should be regarded as exemplary and non-restrictive. The scope of the present invention is defined by the appended claims rather than the above description. Therefore, all changes falling within the meaning and scope of the equivalent elements of the claims are intended to be embraced within the present invention. Any reference signs in the claims should not be construed as limiting the claims involved.

[0079] In addition, it should be understood that although this specification is described according to embodiments, not every embodiment only contains an independent technical solution. This narrative way of the specification is only for clarity. Those skilled in the art should regard the specification as a whole, and the technical solutions in each embodiment can also be appropriately combined to form other embodiments that can be understood by those skilled in the art.

Claims

1. A fully differential coupler, characterized in that, the fully differential coupler includes an input port, a through port, a coupling port and an isolation port, the input port and the isolation port are located on one side of the fully differential coupler, and the through port and the coupling port are located on the other side of the fully differential coupler; the fully differential coupler includes a first input port and a second input port, a first through port and a second through port, a first coupling port and a second coupling port, a first isolation port and a second isolation port, the first input port and the second input port, and the first isolation port and the second isolation port are located on one side of the fully differential coupler, and the first through port and the second through port, and the first coupling port and the second coupling port are located on the other side of the fully differential coupler; in the fully differential coupler: a first inductor is provided between the first input port and the first node, and a third inductor is provided between the first through port and the first node; a second inductor is provided between the second isolation port and the second node, and a fourth inductor is provided between the second coupling port and the second node; a fifth inductor is provided between the second input port and the third node, and a seventh inductor is provided between the second through port and the third node; a sixth inductor is provided between the first isolation port and the fourth node, and an eighth inductor is provided between the first coupling port and the fourth node; wherein, the inductance values of the first inductor to the eighth inductor are all equal, the first inductor and the second inductor, the third inductor and the fourth inductor, the fifth inductor and the sixth inductor, the seventh inductor and the eighth inductor are respectively four groups of mutually coupled inductors, and the coupling coefficients are equal; A coupling capacitor C is provided between the first node and the fourth node, and between the second node and the third node respectively m ; An isolation resistor R is respectively provided between the first isolation port and the reference potential, and between the second isolation port and the reference potential iso .

2. The fully differential coupler according to claim 1, characterized in that, A first parasitic capacitance C is respectively formed between the first input port, the second input port, the first through port, the second through port, the first coupling port, the second coupling port, the first isolation port, the second isolation port, the first node, the second node, the third node, the fourth node and the reference potential g ; A second parasitic capacitance C is respectively formed between the first input port and the second isolation port, between the first through port and the second coupling port, between the second input port and the first isolation port, between the second through port and the first coupling port, between the first node and the second node, and between the third node and the fourth node. f .

3. The fully differential coupler according to claim 1, characterized in that, the first input port and the second input port respectively receive a first differential signal and a second differential signal, the first through port, the second through port, the first coupling port, the second coupling port respectively output a first output signal, a second output signal, a third output signal, a fourth output signal, and the phase differences between the first output signal and the third output signal, the third output signal and the second output signal, the second output signal and the fourth output signal, the fourth output signal and the first output signal are all 90°.

4. A broadband quadrature generator, characterized in that, the broadband quadrature generator includes a first fully differential coupler and two second fully differential couplers, the second fully differential coupler is the fully differential coupler according to any one of claims 1 to 3, the first fully differential coupler includes an input port, a through port, a coupling port and an isolation port, and the input port and the coupling port in the first fully differential coupler are located on one side of the first fully differential coupler, and the through port and the isolation port are located on the other side of the first fully differential coupler.

5. The broadband quadrature generator according to claim 4, characterized in that, The first fully differential coupler includes a first input port, a second input port, a first through port, a second through port, a first coupling port, a second coupling port, a first isolation port, and a second isolation port. The first input port, the second input port, the first coupling port, and the second coupling port are located on one side of the fully differential coupler, and the first through port, the second through port, the first isolation port, and the second isolation port are located on the other side of the fully differential coupler.

6. The broadband quadrature generator according to claim 5, wherein, the first input port and the second input port of the first fully differential coupler respectively receive a first differential signal and a second differential signal; the first through port and the second through port of the first fully differential coupler are respectively connected to the first input port and the second input port of the first second fully differential coupler, and the first coupling port and the second coupling port of the first fully differential coupler are respectively connected to the first input port and the second input port of the second second fully differential coupler; the first coupling port and the second coupling port of the first second fully differential coupler are respectively connected to the first coupling port and the second coupling port of the second second fully differential coupler, and output a first quadrature signal I±; the first through port and the second through port of the first second fully differential coupler are respectively connected to the first through port and the second through port of the second second fully differential coupler, and output a second quadrature signal Q±.

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