Broadband hybrid ring coupler

Abstract

The invention relates to the technical field of radio frequency microwaves, and provides a broadband hybrid ring coupler which comprises a substrate, and the substrate is provided with a first radio frequency component, a second radio frequency component, a fourth radio frequency component, a first inverting transformer and a third radio frequency component. The first radio frequency component, the second radio frequency component, the fourth radio frequency component, the first inverting transformer and the third radio frequency component are sequentially connected to form a ring; the first anti-phase transformer comprises a first inductor and a second inductor, one end of the first inductor is connected with one end of the fourth radio frequency component, one end of the second inductor is connected with one end of the third radio frequency component, and the other end of the first inductor is connected with the other end of the second inductor and then is grounded. Compared with a traditional hybrid ring coupler, the hybrid ring coupler has the advantages that the size of a circuit is reduced, the design difficulty is simplified, and the working bandwidth of the circuit is effectively widened.

Description

Technical Field

[0001] The invention relates to the field of radio frequency microwave technology, and in particular to a broadband hybrid ring coupler. Background Art

[0002] As people's demand for wireless communications grows, communication technology has developed rapidly. As a key component of wireless communication systems, RF devices need to adapt to the complex requirements of modern communication systems, including being able to operate in multiple frequency bands or cover a wider bandwidth. In addition, RF devices also need to be smaller in size and easier to package and integrate.

[0003] In RF systems, couplers are responsible for the distribution, synthesis and isolation of signals and power, and play a vital role. Hybrid ring coupler, also known as rat-competition coupler or hybrid ring. It can output microwave signals in phase or anti-phase according to a specific power ratio, or synthesize two signals into a sum signal or difference signal. Hybrid rings are widely used in various RF system components due to their high isolation independent of balanced loads, such as balanced mixers, push-pull amplifiers, frequency multipliers, antenna feeds, modems, and high-isolation power dividers.

[0004] A traditional hybrid ring coupler consists of three quarter-wavelength transmission lines and one three-quarter-wavelength transmission line. Due to the use of the three-quarter-wavelength transmission line, the working bandwidth is very limited and the space occupied is large, so its application in broadband systems is restricted. Summary of the invention

[0005] The present invention aims to solve at least one of the technical problems existing in the related art. To this end, the present invention provides a broadband hybrid ring coupler, which can effectively reduce the size of the hybrid ring coupler while widening the working bandwidth.

[0006] The present invention provides a broadband hybrid ring coupler, comprising a substrate, wherein a first radio frequency component, a second radio frequency component, a fourth radio frequency component, a first inverter transformer and a third radio frequency component are provided on the substrate; the first radio frequency component, the second radio frequency component, the fourth radio frequency component, the first inverter transformer and the third radio frequency component are connected in sequence to form a ring; the first inverter transformer comprises a first inductor and a second inductor, one end of the first inductor is connected to one end of the fourth radio frequency component, one end of the second inductor is connected to one end of the third radio frequency component, and the other end of the first inductor is connected to the other end of the second inductor and then grounded.

[0007] According to a broadband hybrid ring coupler provided by the present invention, a turns ratio of the first inductor and the second inductor is 1:1, and the first inductor and the second inductor are anti-phase coupled through a magnetic field.

[0008] According to a broadband hybrid ring coupler provided by the present invention, a first port, a second port, a third port, and a fourth port are provided on the substrate; the first port is connected to one end of the first RF component and one end of the second RF component, the second port is connected to the other end of the third RF component and the other end of the first RF component, the third port is connected to the other end of the second RF component and the other end of the fourth RF component, and the fourth port is connected to one end of the third RF component and one end of the second inductor.

[0009] According to a broadband hybrid annular coupler provided by the present invention, the first RF component, the second RF component, the third RF component, and the fourth RF component are all T-coils; the T-coil includes a second inverting transformer and a first capacitor to ground, and the second inverting transformer includes a third inductor and a fourth inductor; the turns ratio of the third inductor and the fourth inductor is 1:1, and the third inductor and the fourth inductor are anti-coupled through a magnetic field; one end of the third inductor is connected to one end of an external circuit, one end of the fourth inductor is connected to the other end of the external circuit, the other end of the third inductor and the other end of the fourth inductor are connected to one end of the first capacitor to ground, and the other end of the first capacitor to ground is grounded.

[0010] According to a broadband hybrid ring coupler provided by the present invention, the first radio frequency component, the second radio frequency component, the third radio frequency component, and the fourth radio frequency component are distributed parameter components or lumped parameter components.

[0011] According to a broadband hybrid ring coupler provided by the present invention, the electrical lengths of the first RF component, the second RF component, the third RF component, and the fourth RF component are all .

[0012] According to a broadband hybrid ring coupler provided by the present invention, an amplitude-phase compensation adjustment network is provided on the substrate, and the amplitude-phase compensation adjustment network includes a fifth inductor, a series capacitor and a second capacitor to ground; one end of the fifth inductor is connected to one end of the third radio frequency component, one end of the series capacitor is connected to one end of the second inductor, one end of the second capacitor to ground is connected to the other end of the fifth inductor and the other end of the series capacitor, the fourth port is connected to one end of the second capacitor to ground, and the other end of the second capacitor to ground is grounded.

[0013] According to a broadband hybrid ring coupler provided by the present invention, magnetic materials are embedded in both the first inductor and the second inductor.

[0014] According to a broadband hybrid ring coupler provided by the present invention, the first inductor and the second inductor are both integrated circuits. Alternatively, the first inductor and the second inductor are both planar single-layer structures or planar multi-layer structures in LTCC.

[0015] The above one or more technical solutions in the embodiments of the present invention have at least one of the following technical effects: The broadband hybrid annular coupler provided by the present invention replaces the traditional three-quarter wavelength transmission line with a section of radio frequency components and an inverting transformer, which not only effectively reduces the size and area, but also expands the working bandwidth of the hybrid annular coupler, so that the hybrid annular coupler can have a larger working bandwidth in a smaller size to adapt to more complex and changeable working conditions, and a reasonably designed inverting transformer can effectively improve the isolation of the hybrid annular coupler and improve its amplitude balance performance and phase balance performance. The parameter design of a section of radio frequency components and an inverting transformer in the present invention is also simpler than that of the traditional three-quarter wavelength transmission line, thereby effectively reducing the design difficulty.

[0016] Additional aspects and advantages of the present invention will be given in part in the following description and in part will be obvious from the following description, or will be learned through practice of the present invention. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] In order to more clearly illustrate the technical solutions in the present invention or the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0018] Figure 1 It is a structural schematic diagram of a broadband hybrid ring coupler provided by the present invention.

[0019] Figure 2 It is a structural schematic diagram of a T-coil of a broadband hybrid annular coupler provided by the present invention.

[0020] Figure 3 The present invention provides a broadband hybrid annular coupler having an amplitude-phase compensation adjustment network.

[0021] Figure 4 It is a simulation result diagram of S parameters when the first port of a broadband hybrid ring coupler provided by the present invention is excited.

[0022] Figure 5 It is a simulation result diagram of S parameters when the fourth port of a broadband hybrid ring coupler provided by the present invention is excited.

[0023] Figure 6 It is a simulation result diagram of amplitude imbalance and phase imbalance of the second port and the third port of a broadband hybrid ring coupler provided by the present invention.

[0024] Reference numerals: 100. Amplitude-phase compensation adjustment network; 11. First RF component; 12. Second RF component; 13. Third RF component; 14. Fourth RF component; 21. First port; 22. Second port; 23. Third port; 24. Fourth port; 31. First inductor; 32. Second inductor; 33. Third inductor; 34. Fourth inductor; 35. Fifth inductor; 41. First capacitor to ground; 42. Second capacitor to ground; 43. Series capacitor. DETAILED DESCRIPTION

[0025] In order to make the purpose, technical scheme and advantages of the present invention clearer, the technical scheme in the present invention will be clearly and completely described below. Obviously, the described embodiments are part of the embodiments of the present invention, rather than all the embodiments. Based on the embodiments in the present invention, all other embodiments obtained by ordinary technicians in the field without creative work are within the scope of protection of the present invention. The following embodiments are used to illustrate the present invention, but cannot be used to limit the scope of the present invention.

[0026] In the description of the embodiments of the present invention, it should be noted that the terms “first”, “second” and “third” are only used for descriptive purposes and cannot be understood as indicating or implying relative importance.

[0027] In the description of the embodiments of the present invention, it should be noted that, unless otherwise clearly specified and limited, the terms "connected" and "connection" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium. For ordinary technicians in this field, the specific meanings of the above terms in the embodiments of the present invention can be understood according to specific circumstances.

[0028] In the description of this specification, the description with reference to the terms "one embodiment", "some embodiments", "example", "specific example", or "some examples" etc. means that the specific features, structures, materials or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the embodiment of the present invention. In this specification, the schematic representations of the above terms do not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described may be combined in any one or more embodiments or examples in a suitable manner. In addition, those skilled in the art may combine and combine the different embodiments or examples described in this specification and the features of the different embodiments or examples, without contradiction.

[0029] Example: See also Figures 1 to 3 , in this embodiment, a broadband hybrid ring coupler is provided.

[0030] Combine the following Figure 1 A broadband hybrid ring coupler provided in an embodiment of the present invention is described. A first RF component 11, a second RF component 12, a third RF component 13, a fourth RF component 14, a first port 21, a second port 22, a third port 23, a fourth port 24 and a first inverter transformer are arranged on a substrate. Specifically, the first RF component 11, the second RF component 12, the fourth RF component 14, the first inverter transformer and the third RF component 13 are connected in sequence to form a ring. The first inverter transformer includes a first inductor 31 and a second inductor 32. One end of the first inductor 31 and the fourth RF component 14 are connected to the first inductor 31. The first RF component 11 is connected to one end of the first RF component 14, one end of the second inductor 32 is connected to one end of the third RF component 13, the other end of the first inductor 31 is connected to the other end of the second inductor 32 and then grounded, the first port 21 is connected to one end of the first RF component 11 and one end of the second RF component 12, the second port 22 is connected to the other end of the third RF component 13 and the other end of the first RF component 11, the third port 23 is connected to the other end of the second RF component 12 and the other end of the fourth RF component 14, and the fourth port 24 is connected to one end of the third RF component 13 and one end of the second inductor 32; Furthermore, the turns ratio of the first inductor 31 and the second inductor 32 is 1:1, the coupling coefficient is k, and the inverse coupling is performed through a magnetic field. The first inverting transformer is used to provide a 180° phase shift, and the first inverting transformer and the fourth RF component 14 can replace the larger three-quarter wavelength transmission line in the traditional hybrid ring coupler, thereby reducing the size of the hybrid ring coupler, and the first inverting transformer and the fourth RF component 14 can also expand the bandwidth of the hybrid ring coupler.

[0031] Figure 2 The schematic diagram of the structure of the T-coil is shown in FIG. The first RF component 11, the second RF component 12, the third RF component 13, and the fourth RF component 14 can be set as T-coils. The use of T-coils can significantly reduce the size of the hybrid annular coupler and reduce the design complexity of the hybrid annular coupler. A T-coil and an inverter transformer provide a 180° phase shift to replace the traditional three-quarter wavelength transmission line, which can not only significantly reduce the size and area, but also greatly expand the working bandwidth of the hybrid annular coupler. The T-coil includes a second inverter transformer and a first ground capacitor 41. The second inverter transformer includes a third inductor 33 and a fourth inductor 34. The turns ratio of the third inductor 33 and the fourth inductor 34 is 1:1, and the coupling coefficient is One end of the third inductor 33 is connected to one end of the external circuit, one end of the fourth inductor 34 is connected to the other end of the external circuit, the other end of the third inductor 33 and the other end of the fourth inductor 34 are connected to one end of the first capacitor 41 to ground, and the other end of the first capacitor 41 to ground is grounded.

[0032] Further, the capacitance C of the first ground capacitor 41 and the inductance L of the third inductor 33 and the fourth inductor 34 are obtained by: First obtain the ABCD matrix of the transmission line and the ABCD matrix of the T coil : in, is the electrical length of the equivalent substituted transmission component, is the center operating frequency, is the characteristic impedance, represents an imaginary unit, and Known, It can be derived based on the expressions and connection relationships of the components of the T coil. It can be deduced that: Furthermore, the first RF component 11, the second RF component 12, the third RF component 13, and the fourth RF component 14 can be implemented by distributed parameter elements or lumped parameter elements, and the distributed parameter elements include microstrip lines, strip lines, waveguides, coplanar waveguides, slot lines, fin lines, suspended strip lines, optical waveguides, and other distributed parameter elements; the lumped parameter elements include high-pass Type network, low pass The first RF component 11, the second RF component 12, the third RF component 13, and the fourth RF component 14 can all be distributed parameter components or all be lumped parameter components, or some can be distributed parameter components and some can be lumped parameter components.

[0033] Furthermore, the electrical lengths of the first RF component 11, the second RF component 12, the third RF component 13, and the fourth RF component 14 are all , the characteristic impedance is ,in For port matching impedance, it can be obtained according to the parameters of the first port 21 , the second port 22 , the third port 23 and the fourth port 24 .

[0034] Figure 3 The present invention is a schematic diagram of the structure of a broadband hybrid ring coupler with an amplitude-phase compensation adjustment network 100, which can effectively reduce amplitude error and phase error, and can effectively reduce return loss. The amplitude-phase compensation adjustment network 100 is arranged on a substrate, and includes a fifth inductor 35, a series capacitor 43, and a second capacitor to ground 42; one end of the fifth inductor 35 is connected to one end of the third RF component 13, the other end of the fifth inductor 35 is connected to one end of the second capacitor to ground 42, one end of the series capacitor 43 is connected to one end of the second inductor 32, the other end of the series capacitor 43 is connected to one end of the second capacitor to ground 42, the fourth port 24 is connected to one end of the second capacitor to ground 42, and the other end of the second capacitor to ground 42 is grounded.

[0035] Among them, the series capacitor 43 is used to make the phase change of the signal transmitted by the hybrid ring coupler flat and compensate for part of the amplitude imbalance, the fifth inductor 35 is used to improve the phase balance interval and compensate for part of the amplitude imbalance, and the second capacitor to ground 42 is used to improve the return loss of the fourth port 24; the amplitude-phase compensation adjustment network 100 can improve the phase change of the signal, adjust the phase balance interval, compensate for the amplitude imbalance of the signal in the hybrid ring coupler, and reduce the return loss of the port, thereby improving the signal quality, reducing errors, and realizing accurate data transmission and processing.

[0036] Furthermore, magnetic materials may be embedded in the first inductor 31 , the second inductor 32 , the third inductor 33 , the fourth inductor 34 and the fifth inductor 35 to increase their inductance values.

[0037] Furthermore, the first inductor 31, the second inductor 32, the third inductor 33, the fourth inductor 34 and the fifth inductor 35 may be manufactured using an integrated circuit process; or may be manufactured using a planar single-layer structure or a planar multi-layer structure in an LTCC (Low Temperature Co-fired Ceramic) process to reduce size and improve circuit integration.

[0038] The size of the core circuit of the embodiment of the present invention is 422 ×323.4 , with the characteristics of miniaturization and integration.

[0039] The present invention also simulates a broadband hybrid ring coupler, where the working center frequency selected in the simulation is 14 GHz, the port matching impedance is selected as 50 Ohm, and the characteristic impedance of all transmission components is selected as 70.7 Ohm. The inductance value of the first inductor 31 and the second inductor 32 is 1 nH, and the coupling coefficient k is 0.64. The capacitance value of the series capacitor 43 is 640 fF. The coupling coefficient of the third inductor 33 and the fourth inductor 34 is 1.3 k. The third inductor 33 and the fourth inductor 34 are calculated according to the formula to obtain an inductance value of 571.8 pH, and the first ground capacitor 41 is calculated according to the formula to obtain a capacitance value of 307.7 fF. The capacitance value of the second ground capacitor 42 is 80 fF. The simulation results are as follows: Figure 4 , Figure 5 and Figure 6 shown.

[0040] Figure 4 Schematic diagram of S parameters when the first port of the broadband hybrid ring coupler is excited, wherein the first port 21 is an input port, the second port 22 and the third port 23 are output ports, the fourth port 24 is an isolation port, S11 is the return loss of the first port 21, S21 is the insertion loss of the second port 22, S31 is the insertion loss of the third port 23, S41 is the isolation between the first port 21 and the fourth port 24, and S32 is the isolation between the second port 22 and the third port 23. Figure 4 It can be seen that when the first port 21 is excited, the frequency range in which its return loss is less than -14.57 dB is 10.763 GHz to 17.20 GHz, and the relative bandwidth reaches 46.0%.

[0041] Figure 5 Schematic diagram of S parameters when the fourth port of the broadband hybrid ring coupler is excited, wherein the fourth port 24 is an input port, the second port 22 and the third port 23 are output ports, the first port 21 is an isolation port, S44 is the return loss of the fourth port 24, S24 is the insertion loss of the second port 22, S34 is the insertion loss of the third port 23, and S41 is the isolation between the fourth port 24 and the first port 21. Figure 5 It can be seen that when the fourth port 24 is excited, the frequency range in which its return loss is less than -10 dB is 10.78 GHz to 17.20 GHz, and the relative bandwidth reaches 45.89%, and Figure 4 and Figure 5 The isolation performance between the isolation port and the input port is greater than 18.26dB in the passband range of 10.763GHz to 17.20GHz.

[0042] Figure 6Graph showing simulation results of amplitude imbalance and phase imbalance of the second port 22 and the third port 23 of the broadband hybrid ring coupler, wherein |S21|-|S31| is the amplitude imbalance when the first port 21 is used as the input port, |S24|-|S34| is the amplitude imbalance when the fourth port 24 is used as the input port, ∠|S21|-∠|S31| is the phase imbalance when the first port 21 is used as the input port, and ∠|S24|-∠|S34| is the phase imbalance when the fourth port 24 is used as the input port; Figure 6 The left axis is the amplitude balance, and the right axis is the phase balance. Figure 6 As shown on the left axis, the amplitude imbalance (|S21|-|S31|) is less than 0.95dB in the passband range of 10.763GHz to 17.20GHz, and the amplitude imbalance (|S24|-|S34|) is less than 0.48dB. Figure 6 As shown on the right axis, in the passband range of 10.763 GHz to 17.20 GHz, when the excitation signal is applied to the first port 21, the phase imbalance (∠|S21|-∠|S31|) is less than 2.05°; when the excitation signal is applied to the fourth port 24, the phase imbalance (∠|S24|-∠|S34|) is 180°±5°. The results of the above simulation data show that the present invention has relatively good amplitude and phase balance performance and can cover a wider frequency range.

[0043] In summary, the broadband hybrid ring coupler provided by the present invention enables the hybrid ring coupler to have a larger working bandwidth in a smaller size, and the inverting transformer can effectively improve the isolation of the hybrid ring coupler and optimize its amplitude balance performance and phase balance performance, and the return loss of the output port is also low, which can effectively improve the performance of the hybrid ring coupler.

[0044] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit it. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or make equivalent replacements for some of the technical features therein. However, these modifications or replacements do not deviate the essence of the corresponding technical solutions from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. A broadband hybrid ring coupler, characterized in that: The invention comprises a substrate, on which a first radio frequency component, a second radio frequency component, a fourth radio frequency component, a first inverter transformer and a third radio frequency component are provided; the first radio frequency component, the second radio frequency component, the fourth radio frequency component, the first inverter transformer and the third radio frequency component are connected in sequence to form a ring; the first inverter transformer comprises a first inductor and a second inductor, one end of the first inductor is connected to one end of the fourth radio frequency component, one end of the second inductor is connected to one end of the third radio frequency component, and the other end of the first inductor is connected to the other end of the second inductor and then grounded.

2. The broadband hybrid ring coupler according to claim 1, characterized in that: The turns ratio of the first inductor and the second inductor is 1:1, and the first inductor and the second inductor are anti-phase coupled through a magnetic field.

3. The broadband hybrid ring coupler according to claim 1, characterized in that: The substrate is provided with a first port, a second port, a third port and a fourth port; the first port is connected to one end of the first RF component and one end of the second RF component, the second port is connected to the other end of the third RF component and the other end of the first RF component, the third port is connected to the other end of the second RF component and the other end of the fourth RF component, and the fourth port is connected to one end of the third RF component and one end of the second inductor.

4. The broadband hybrid ring coupler according to claim 1, characterized in that: The first RF component, the second RF component, the third RF component, and the fourth RF component are all T-coils; the T-coil includes a second inverter transformer and a first capacitor to ground, and the second inverter transformer includes a third inductor and a fourth inductor; the turns ratio of the third inductor and the fourth inductor is 1:1, and the third inductor and the fourth inductor are anti-coupled through a magnetic field; one end of the third inductor is connected to one end of an external circuit, one end of the fourth inductor is connected to the other end of the external circuit, the other end of the third inductor and the other end of the fourth inductor are connected to one end of the first capacitor to ground, and the other end of the first capacitor to ground is grounded.

5. The broadband hybrid ring coupler according to claim 1, characterized in that: The first RF component, the second RF component, the third RF component and the fourth RF component are distributed parameter components or lumped parameter components.

6. The broadband hybrid ring coupler according to claim 1, characterized in that: The electrical lengths of the first RF component, the second RF component, the third RF component, and the fourth RF component are all .

7. The broadband hybrid ring coupler according to claim 1, characterized in that: An amplitude-phase compensation adjustment network is provided on the substrate, and the amplitude-phase compensation adjustment network includes a fifth inductor, a series capacitor and a second capacitor to ground; one end of the fifth inductor is connected to one end of the third RF component, one end of the series capacitor is connected to one end of the second inductor, one end of the second capacitor to ground is connected to the other end of the fifth inductor and the other end of the series capacitor, the fourth port is connected to one end of the second capacitor to ground, and the other end of the second capacitor to ground is grounded.

8. The broadband hybrid ring coupler according to claim 1, characterized in that: Magnetic materials are embedded in the first inductor and the second inductor.

9. The broadband hybrid ring coupler according to claim 1, characterized in that: The first inductor and the second inductor are both integrated circuits, or the first inductor and the second inductor are both planar single-layer structures or planar multi-layer structures in LTCC.

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