Lumped-parameter filter coupler

Abstract

The present invention discloses a lumped parameter filter coupler, wherein the ports Port1, Port2, Port3 and Port4 thereon are respectively connected to a resonance module; the four resonance modules are connected to the same coupling module; when Port1 is the signal input port, Port2 and Port3 are the co-directional output ports, Port4 is used as the isolation port, the center frequencies of the signals output by Port2 and Port3 are both the preset center frequency, and the power is equal and the phase difference is the preset angle; when Port4 is the signal input port, Port2 and Port3 are used as the reverse output ports, Port1 is used as the isolation port, the center frequencies of the signals output by Port2 and Port3 are both the preset center frequency, and the power is equal and the phase difference is the preset angle. The present invention uses lumped parameters to simultaneously achieve the filtering and coupling functions, effectively reducing the size of the circuit.

Description

Technical Field

[0001] The present invention relates to the technical field of radio frequency and microwave circuits, and particularly to a lumped parameter filter coupler. Background Art

[0002] With the development of radio frequency circuit technology, radio frequency circuits are gradually tending towards miniaturization and multi-functionality. To achieve circuit multi-functionality, the most common approach is to directly cascade and splice two or more circuits with different functions together, and then, to achieve miniaturization by optimizing the circuit layout and parameters. In this way, the circuit size will be relatively large.

[0003] Distributed circuits and lumped parameter circuits are two types of circuits with different characteristics. Among them, a distributed circuit is a radio frequency circuit mainly composed of a transmission line structure, and a lumped parameter circuit is a radio frequency circuit composed of discrete components such as capacitors and inductors. Compared with distributed circuits, the components such as capacitors and inductors in lumped parameter circuits are smaller in size and can be flexibly arranged. Therefore, in the low-frequency band, lumped parameter circuits have the advantage of miniaturization.

[0004] A filter coupler is a device that combines filtering characteristics and power distribution, and can simultaneously implement the filtering function and the coupler function. Currently, the existing filter couplers usually adopt the distributed circuit type, and their circuit area is large, especially relatively large in the low-frequency band. Summary of the Invention

[0005] The object of the present invention is to provide a lumped parameter filter coupler for the technical defects existing in the prior art.

[0006] To this end, the present invention provides a lumped parameter filter coupler, which includes port Port1, port Port2, port Port3, and port Port4;

[0007] Port Port1, port Port2, port Port3, and port Port4 are respectively connected to a resonance module;

[0008] The four resonance modules are connected to the same coupling module;

[0009] The resonance module includes at least one inductor and at least one capacitor;

[0010] The coupling module includes at least one inductor and / or at least one capacitor;

[0011] When port Port1 is the signal input port, port Port2 and port Port3 serve as co-directional output ports, and port Port4 serves as an isolation port. At this time, the center frequencies of the signals output from port Port2 and port Port3 are both the preset center frequency, and the power is equal and the phase difference is the preset angle;

[0012] When Port4 is a signal input port, Port2 and Port3 are used as reverse output ports, and Port1 is used as an isolation port. At this time, the center frequencies of the signals output by Port2 and Port3 are both the preset center frequency, and they have equal power and a phase difference of a preset angle.

[0013] Preferably, when Port4 is a signal input port, the phase difference between the signals output by Port2 and Port3 is 180°, and Port1 is used as an isolation port, the four resonant modules specifically include a first resonant module, a second resonant module, a third resonant module, and a fourth resonant module;

[0014] Among them, the first resonant module includes inductor L102, inductor L104, and capacitor C102;

[0015] Inductor L102 is connected in parallel with the series branch composed of inductor L104 and capacitor C102;

[0016] One end of inductor L102 and one end of inductor L104 are grounded;

[0017] The second resonant module includes inductor L203, inductor L205, and capacitor C203;

[0018] Inductor L203 is connected in parallel with the series branch composed of inductor L205 and capacitor C203;

[0019] One end of inductor L203 and one end of capacitor C203 are grounded;

[0020] The third resonant module includes inductor L302, inductor L304, and capacitor C302;

[0021] Inductor L302 is connected in parallel with the series branch composed of inductor L304 and capacitor C302;

[0022] One end of inductor L302 and one end of inductor L304 are grounded;

[0023] The fourth resonant module includes inductor L403, inductor L405, and capacitor C403;

[0024] Inductor L403 is connected in parallel with the series branch composed of inductor L405 and capacitor C403;

[0025] One end of inductor L403 and one end of capacitor C403 are grounded;

[0026] Among them, the coupling module specifically uses the first coupling module;

[0027] The first coupling module includes an inductor L11, an inductor L12, an inductor L13, and a capacitor C11 that are connected in sequence;

[0028] Among them, the connection node A1 between the inductor L11 and the inductor L12 is respectively connected to the port Port1, the other end of the inductor L102, and one end of the capacitor C102;

[0029] The connection node B1 between the inductor L11 and the capacitor C11 is respectively connected to the port Port2, the other end of the inductor L203, and one end of the inductor L205;

[0030] The connection node C1 between the inductor L12 and the inductor L13 is respectively connected to the port Port3, the other end of the inductor L302, and one end of the capacitor C302;

[0031] The connection node D1 between the inductor L13 and the capacitor C11 is respectively connected to the port Port4, the other end of the inductor L403, and one end of the inductor L405.

[0032] Preferably, for the first resonance module and the third resonance module, the inductance values of the inductor L102 and the inductor L302 are equal, and the same inductor is used;

[0033] The inductance values of the inductor L104 and the inductor L304 are equal, and the same inductor is used;

[0034] The capacitance values of the capacitor C102 and the capacitor C302 are equal, and the same capacitor is used.

[0035] Preferably, for the second resonance module and the fourth resonance module, the inductance values of the inductor L203 and the inductor L403 are equal, and the same inductor is used;

[0036] The inductance values of the inductor L205 and the inductor L405 are equal, and the same inductor is used;

[0037] The capacitance values of the capacitor C203 and the capacitor C403 are equal, and the same capacitor is used.

[0038] Preferably, for the first coupling module, the inductance values of the inductor L11, the inductor L12, and the inductor L13 are equal, and the same inductor is used.

[0039] Preferably, when the port Port1 is a signal input port, the signals output from the port Port2 and the port Port3 have a phase difference of 90°, and the port Port4 is an isolation port, the four resonance modules specifically include a fifth resonance module, a sixth resonance module, a seventh resonance module, and an eighth resonance module;

[0040] Among them, the fifth resonance module includes an inductor L503 and a capacitor C503;

[0041] Inductor L503 and capacitor C503 are connected in parallel;

[0042] One end of inductor L503 and one end of capacitor C503 are grounded;

[0043] The sixth resonance module includes inductor L603 and capacitor C603;

[0044] Inductor L603 and capacitor C603 are connected in parallel;

[0045] One end of inductor L603 and one end of capacitor C603 are grounded;

[0046] The seventh resonance module includes inductor L703 and capacitor C703;

[0047] Inductor L703 and capacitor C703 are connected in parallel;

[0048] One end of inductor L703 and one end of capacitor C703 are grounded;

[0049] The eighth resonance module includes inductor L803 and capacitor C803;

[0050] Inductor L803 and capacitor C803 are connected in parallel;

[0051] One end of inductor L803 and one end of capacitor C803 are grounded;

[0052] Among them, the coupling module specifically adopts the second coupling module;

[0053] Among them, the second coupling module includes inductors L21, L22, L23, and L24 connected in sequence;

[0054] The connection node A2 between inductor L21 and inductor L24 is respectively connected to port Port1, the other end of inductor L503, and the other end of capacitor 503;

[0055] The connection node B2 between inductor L21 and inductor L22 is respectively connected to port Port2, the other end of inductor L603, and the other end of capacitor 603;

[0056] The connection node C2 between inductor L22 and inductor L23 is respectively connected to port Port3, the other end of inductor L703, and the other end of capacitor 703;

[0057] The connection node D2 between inductor L23 and inductor L24 is respectively connected to port Port4, the other end of inductor L803, and the other end of capacitor 803.

[0058] Preferably, for the fifth resonance module, the sixth resonance module, the seventh resonance module, and the eighth resonance module, the inductance values of the inductor L503, the inductor L603, the inductor L703, and the inductor L803 are equal, and the same inductor is used;

[0059] the capacitance values of the capacitor C503, the capacitor C603, the capacitor C703, and the capacitor C803 are equal, and the same capacitor is used.

[0060] Preferably, for the second coupling module, the inductance values of the inductor L21 and the inductor L23 are equal, and the same inductor is used; the inductance values of the inductor L22 and the inductor L24 are equal, and the same inductor is used.

[0061] As can be seen from the technical solutions provided by the present invention above, compared with the prior art, the lumped parameter filter coupler provided by the present invention has a scientific design, uses lumped parameters to simultaneously achieve the filter coupling function, can effectively reduce the size of the circuit, and has great practical significance.

[0062] For the lumped parameter filter coupler of the present invention, it integrates the filter function and the coupling function, realizes two functions with one circuit, and adopts a lumped parameter circuit, making it easy to make the size of the circuit very small in the low frequency band.

[0063] In addition, the lumped parameter filter coupler provided by the present invention can also adjust the center frequency, coupling degree, coupling bandwidth, and output phase of the filter by adjusting the sizes of the lumped parameter capacitors and inductors of the topology and the topology of the coupler part, having the advantage of flexible design. BRIEF DESCRIPTION OF THE DRAWINGS

[0064] Figure 1 is the schematic diagram of the lumped parameter filter coupler provided by the present invention when it is a 180-degree lumped parameter band-pass filter coupler;

[0065] Figure 2 is the cross-sectional view of the 180-degree lumped parameter band-pass filter coupler implemented based on the dielectric integrated suspended line circuit;

[0066] Figure 3a is the three-dimensional perspective view of the 180-degree lumped parameter band-pass filter coupler implemented based on the dielectric integrated suspended line circuit;

[0067] Figure 3b is the top view of the core circuit plane of the G5 metal layer in the 180-degree lumped parameter band-pass filter coupler implemented based on the dielectric integrated suspended line circuit;

[0068] Figure 3c is the top view of the core circuit plane of the G6 metal layer in the 180-degree lumped parameter band-pass filter coupler implemented based on the dielectric integrated suspended line circuit;

[0069] Figure 4a The parameters of the 180-degree lumped-parameter filter coupler for testing are the scattering parameter response diagrams of Port 1, Port 2, Port 3, and Port 4 when the input of Port 1 is in-phase output;

[0070] Figure 4b The parameters of the 180-degree lumped-parameter filter coupler for testing are the scattering parameter response diagrams of Port 1, Port 2, Port 3, and Port 4 when the input of Port 4 is 180-degree phase output;

[0071] Figure 4c The parameters of the 180-degree lumped-parameter filter coupler for testing are the schematic diagrams of the phase imbalance parameters between Port 2 and Port 3 when the output is in-phase and 180-degree phase output;

[0072] Figure 5 The lumped-parameter filter coupler provided by the present invention is the schematic diagram when it is a 90-degree lumped-parameter bandpass filter coupler;

[0073] Figure 6 The schematic diagram of another 180-degree lumped-parameter filter coupler proposed by the present invention;

[0074] Figure 7 The schematic diagram of another 90-degree lumped-parameter filter coupler proposed by the present invention. Specific embodiments

[0075] Next, the technical solutions of the present invention will be clearly and completely described in conjunction with 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.

[0076] In the description of the present invention, it should be understood that the orientation or positional relationship indicated by the terms "center", "longitudinal", "transverse", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", etc. is based on the orientation or positional relationship shown in the drawings. It is only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation. Therefore, it should not be construed as a limitation to the present invention. In addition, the terms "first", "second", etc. are only used for descriptive purposes and cannot be understood as indicating or implying relative importance or implicitly specifying the quantity of the indicated technical features. Thus, the features defined with "first", "second", etc. may explicitly or implicitly include one or more of such features. In the description of the present invention, unless otherwise specified, the meaning of "plural" is two or more.

[0077] In the description of the present invention, it should be noted that unless otherwise clearly specified and defined, the terms "mounted", "connected", "coupled" should be understood in a broad sense. For example, it may be a fixed connection, a detachable connection, or an integral connection; it may be a mechanical connection or an electrical connection; it may be directly connected or indirectly connected through an intermediate medium, and it may be the communication inside two elements. For those of ordinary skill in the art, the specific meanings of the above terms in the present invention can be understood through specific circumstances.

[0078] The present invention will be described in detail below with reference to the drawings and in combination with embodiments.

[0079] See Figures 1 to 7 , the present invention provides a lumped parameter filter coupler, including port Port1, port Port2, port Port3, and port Port4 (i.e., interface 1, interface 2, interface 3, and interface 4);

[0080] Port Port1, port Port2, port Port3, and port Port4 are respectively connected to a resonance module;

[0081] The four resonance modules are connected to the same coupling module;

[0082] The resonance module includes at least one inductor and at least one capacitor, and is used to implement the band-pass filtering function;

[0083] The coupling module includes at least one inductor and / or at least one capacitor, and is used to implement the coupling function;

[0084] When Port1 is a signal input port, Port2 and Port3 serve as co-directional output ports, and Port4 serves as an isolation port. At this time, the center frequencies of the signals output from Port2 and Port3 are both the preset center frequency (for example, 1 GHz), and they have equal power and a phase difference of a preset angle.

[0085] It should be noted that the lumped parameter filter coupler of the present invention is mainly used in scenarios in radio frequency devices or radio frequency systems where a radio frequency device or radio frequency system needs to distribute a signal into two signals in a certain power ratio, and the two output signals maintain co-directionality or a preset angle phase difference within a certain frequency band range. At the same time, it is necessary to filter the two output signals, and it is usually used in circuits such as antennas, phase shifters, and amplifiers. Therefore, for the present invention, when Port1 is a signal input port, Port1 is connected to the output port of the previous-stage device; the signals processed by the filter coupler are output from the co-directional output port Port2 and the co-directional output port Port3, and the two ports (i.e., Port2 and Port3) are connected to the input ports of the subsequent-stage devices; the isolation port Port4 is left floating or connected to a matching load at this time.

[0086] When Port4 is a signal input port, Port2 and Port3 serve as reverse output ports, and Port1 serves as an isolation port. At this time, the center frequencies of the signals output from Port2 and Port3 are both the preset center frequency (for example, 1 GHz), and they have equal power and a phase difference of a preset angle (for example, 180° or 90°).

[0087] It should be noted that when Port4 is a signal input port, Port4 is connected to the output port of the previous-stage device; the signals processed by the filter coupler are output from the output port Port2 and the output port Port3 at this time, and the two ports (i.e., Port2 and Port3) are connected to the input ports of the subsequent-stage devices; the isolation port Port1 is left floating or connected to a matching load at this time.

[0088] Embodiment 1.

[0089] Taking the 180-degree lumped parameter filter coupler as an example, using the Rat-Race coupling topology, the proposed topology is as Figure 1 shown. In this embodiment, it includes 11 inductors and 5 capacitors.

[0090] In the present invention, refer to Figure 1, when Port4 is a signal input port, the signals output from Port2 and Port3 have a phase difference of 180°, and Port1 is an isolation port, the four resonant modules specifically include a first resonant module, a second resonant module, a third resonant module, and a fourth resonant module;

[0091] Among them, the first resonant module includes inductor L102, inductor L104, and capacitor C102;

[0092] Inductor L102 is connected in parallel with the series branch composed of inductor L104 and capacitor C102;

[0093] One end of inductor L102 and one end of inductor L104 are grounded;

[0094] The second resonant module includes inductor L203, inductor L205, and capacitor C203;

[0095] Inductor L203 is connected in parallel with the series branch composed of inductor L205 and capacitor C203;

[0096] One end of inductor L203 and one end of capacitor C203 are grounded;

[0097] The third resonant module includes inductor L302, inductor L304, and capacitor C302;

[0098] Inductor L302 is connected in parallel with the series branch composed of inductor L304 and capacitor C302;

[0099] One end of inductor L302 and one end of inductor L304 are grounded;

[0100] The fourth resonant module includes inductor L403, inductor L405, and capacitor C403;

[0101] Inductor L403 is connected in parallel with the series branch composed of inductor L405 and capacitor C403;

[0102] One end of inductor L403 and one end of capacitor C403 are grounded;

[0103] Among them, the coupling module specifically adopts a first coupling module;

[0104] The first coupling module includes inductor L11, inductor L12, inductor L13, and capacitor C11 connected in sequence;

[0105] Among them, the connection node A1 between inductor L11 and inductor L12 is respectively connected to Port1, the other end of inductor L102, and one end of capacitor C102;

[0106] The connection node B1 between the inductor L11 and the capacitor C11 is respectively connected to the port Port2, the other end of the inductor L203, and one end of the inductor L205;

[0107] The connection node C1 between the inductor L12 and the inductor L13 is respectively connected to the port Port3, the other end of the inductor L302, and one end of the capacitor C302;

[0108] The connection node D1 between the inductor L13 and the capacitor C11 is respectively connected to the port Port4, the other end of the inductor L403, and one end of the inductor L405.

[0109] In specific implementation, for the first resonance module and the third resonance module, the inductance values of the inductor L102 and the inductor L302 are equal, and the same inductor is used;

[0110] The inductance values of the inductor L104 and the inductor L304 are equal, and the same inductor is used;

[0111] The capacitance values of the capacitor C102 and the capacitor C302 are equal, and the same capacitor is used.

[0112] In specific implementation, for the second resonance module and the fourth resonance module, the inductance values of the inductor L203 and the inductor L403 are equal, and the same inductor is used;

[0113] The inductance values of the inductor L205 and the inductor L405 are equal, and the same inductor is used;

[0114] The capacitance values of the capacitor C203 and the capacitor C403 are equal, and the same capacitor is used.

[0115] In specific implementation, for the first coupling module, the inductance values of the inductor L11, the inductor L12, and the inductor L13 are equal, and the same inductor is used.

[0116] It should be noted that Figure 1 The circuit structure of the shown 180-degree lumped parameter band-pass filter coupler is composed of 11 inductors and 5 capacitors. 8 inductors and 4 capacitors are distributed around the circuit to form resonators to provide filtering performance, and the remaining 3 inductors and 1 capacitor in the middle mainly provide coupling performance.

[0117] In specific implementation, the inductance values of the inductor L11, the inductor L12, and the inductor L13 are 11.05 nH;

[0118] The inductance values of the inductor L102 and the inductor L302 are 3.02 nH;

[0119] The inductance values of the inductor L203 and the inductor L403 are 3.95 nH;

[0120] The inductance values of inductor L104 and inductor L304 are 7.32 nH;

[0121] The capacitance value of capacitor C11 is 1.86 pF;

[0122] The capacitance values of capacitor C102 and capacitor C302 are 2.02 pF;

[0123] The capacitance values of capacitor C203 and capacitor C403 are 2.59 pF. Thus, the filter coupler obtained by the design of the present invention is a -3 dB coupler, and the center frequency is 1 GHz.

[0124] Specifically, the 180-degree lumped parameter bandpass filter coupler of the first embodiment can be implemented on a dielectric integrated suspended line platform, and its cross-sectional view and three-dimensional view are respectively as Figure 2 shown in and Figure 3. The dielectric integrated suspended line is a 5-layer structure, as Figure 2 、 Figure 3a shown. Each layer structure is a double-sided PCB (printed circuit board), and each layer of PCB is composed of a layer of dielectric and metals on both sides. The 5 dielectric layers are respectively named S1 to S5, and the materials and thicknesses of S1 to S5 are: Fr4 (0.6 mm), Fr4 (2 mm), Rogers RO4350 (0.254 mm), Fr4 (2 mm), and Fr4 (0.6 mm). Among them, the dielectric layers S1 and S5 and the metals on both sides thereof serve as shielding layers, and cavities are formed by hollowing out the interiors of S2 and S4; the metals on both sides of the 5 dielectric layers are respectively named G1 to G10. Among them, the circuit is mainly designed on the G5 and G6 layers, and the other metal layers mainly serve as grounds.

[0125] The plan view of the G5 metal layer is as Figure 3b shown, and the inductors and capacitors in this figure correspond to the respective capacitors and inductors in Figure 1 . The capacitor uses a trapezoidal flat capacitor, and using a trapezoid is beneficial to more efficiently utilize space and reduce the overall circuit size. The inductor uses a suspended line instead of an inductor. The specific layout parameters are obtained with the help of electromagnetic simulation software.

[0126] In the first embodiment, the S-parameters and the coupling port phase imbalance results of the measured filter coupler are as Figure 4a 、 Figure 4b and Figure 4c shown. The center frequency of the processed and tested filter coupler is 1 GHz. For the input of Port1, the fractional bandwidth FBW is 6%, and the measured S21 and S31 within the passband from 0.97 GHz to 1.03 GHz are at -(3 + 2) dB, and the difference between S21 and S31 is within 1 dB. The in-band return loss is less than 12 dB, the isolation is greater than 29.1 dB, and the measured phase imbalance is 0 ± 5 degrees;

[0127] For the input of Port 4, the bandwidth ratio FBW is 6%, the measured S21 and S31 within the passband are at -(3 + 2) dB, the difference between S21 and S31 is within 1.1 dB, the in-band return loss is less than 10 dB, the isolation is greater than 28.5 dB, and the measured phase imbalance is 180 ± 8 degrees.

[0128] Figure 4a The scattering parameter results when the first port (i.e., Port1) of the measured 180-degree lumped parameter filter coupler is input are shown. Among them, the abscissa represents the frequency of the input signal of the first port (i.e., Port1), in GHz; the ordinate represents the scattering parameters of each port, expressed in decibels. S11 represents the scattering parameter measured at the first port (i.e., Port1) when the first port (i.e., Port1) is input, that is, the return loss of the first port (i.e., Port1); S21 and S31 respectively represent the scattering parameters of the second port (i.e., Port2) and the third port (i.e., Port3) when the first port (i.e., Port1) is input, that is, the insertion losses of the second port (i.e., Port2) and the third port (i.e., Port3); S41 represents the scattering parameter of the fourth port (i.e., Port4), that is, the isolation between the first port (i.e., Port1) and the fourth port (i.e., Port4). This figure shows that the processed circuit can achieve the filtering and coupling functions when the first port (i.e., Port1) of the filter coupler is input within a certain frequency band.

[0129] Figure 4b The scattering parameter results when the four ports of the measured 180-degree lumped parameter filter coupler are input are shown. Among them, the abscissa represents the frequency of the input signal of the fourth port (i.e., Port4), in GHz; the ordinate represents the scattering parameters of each port, expressed in decibels. S44 represents the scattering parameter measured at the fourth port (i.e., Port4) when the fourth port (i.e., Port4) is input, that is, the return loss of the fourth port (i.e., Port4); S24 and S34 respectively represent the scattering parameters of the second port (i.e., Port2) and the third port (i.e., Port3) when the fourth port (i.e., Port4) is input, that is, the insertion losses of the second port (i.e., Port2) and the third port (i.e., Port3); S14 represents the scattering parameter of the fourth port (i.e., Port4), that is, the isolation between the fourth port (i.e., Port4) and the first port (i.e., Port1). This figure shows that the processed circuit can achieve the filtering and coupling functions when the fourth port (i.e., Port4) of the filter coupler is input within a certain frequency band.

[0130] Figure 4cThe measured phase imbalance results of the first port (i.e., Port 1) and the four ports of the 180-degree lumped parameter filter coupler are shown. The horizontal axis represents the frequency of the input signal of the first port (i.e., Port 1) or the fourth port (i.e., Port 4), in GHz; the vertical axis represents the phase imbalance of the output signal, in decibels. The phase imbalance when the first port (i.e., Port 1) is input is calculated by the difference between the phase of the output scattering parameter S21 of the second port (i.e., Port 2) and the phase of the output scattering parameter S31 of the third port (i.e., Port 3). The phase imbalance when the fourth port (i.e., Port 4) is input is calculated by the difference between the phase of the output scattering parameter S24 of the second port (i.e., Port 2) and the phase of the output scattering parameter S34 of the third port (i.e., Port 3). As can be seen from the figure, the phase imbalance of the two ports does not fluctuate much within the working frequency band of 0.97GHz to 1.03GHz. The figure shows that the processed circuit can achieve the same-direction output and 180-degree phase output functions when the first port (i.e., port Port1) and the fourth port (i.e., port Port4) of the filter coupler are input within a certain frequency band.

[0131] The above shows that the lumped parameter filter coupler of the present invention can be implemented on a dielectric integrated suspension line platform. The proposed topology has strong implementation power and can simultaneously have filtering and coupling functions. At the same time, the circuit size is small, only 0.013λ 0 ×0.006λ 0 , where λ 0 is the wavelength at the center frequency. At the same time, the filter coupler has the characteristics of self-packaging of the dielectric integrated suspension line itself and low loss.

[0132] Embodiment 2.

[0133] To illustrate the feasibility of other types of filter couplers, Figure 5 A 90-degree coupled filter coupler topology is proposed. The filter coupler uses a branch line coupling topology to achieve the coupling function and integrates a parallel resonator into the input and output ends to achieve the filtering function.

[0134] In the present invention, see Figure 5 , when port Port1 is a signal input port, the phases of the signals output by port Port2 and port Port3 differ by 90°, and port Port4 is used as an isolation port, the four resonance modules specifically include a fifth resonance module, a sixth resonance module, a seventh resonance module, and an eighth resonance module;

[0135] Wherein, the fifth resonance module includes an inductor L503 and a capacitor C503;

[0136] The inductor L503 and the capacitor C503 are connected in parallel.

[0137] One end of the inductor L503 and one end of the capacitor C503 are grounded.

[0138] The sixth resonance module includes an inductor L603 and a capacitor C603.

[0139] The inductor L603 and the capacitor C603 are connected in parallel.

[0140] One end of the inductor L603 and one end of the capacitor C603 are grounded.

[0141] The seventh resonance module includes an inductor L703 and a capacitor C703.

[0142] The inductor L703 and the capacitor C703 are connected in parallel.

[0143] One end of the inductor L703 and one end of the capacitor C703 are grounded.

[0144] The eighth resonance module includes an inductor L803 and a capacitor C803.

[0145] The inductor L803 and the capacitor C803 are connected in parallel.

[0146] One end of the inductor L803 and one end of the capacitor C803 are grounded.

[0147] Among them, the coupling module specifically adopts the second coupling module.

[0148] Among them, the second coupling module includes inductors L21, L22, L23, and L24 connected in sequence.

[0149] The connection node A2 between the inductor L21 and the inductor L24 is respectively connected to the port Port1, the other end of the inductor L503, and the other end of the capacitor 503.

[0150] The connection node B2 between the inductor L21 and the inductor L22 is respectively connected to the port Port2, the other end of the inductor L603, and the other end of the capacitor 603.

[0151] The connection node C2 between the inductor L22 and the inductor L23 is respectively connected to the port Port3, the other end of the inductor L703, and the other end of the capacitor 703.

[0152] The connection node D2 between the inductor L23 and the inductor L24 is respectively connected to the port Port4, the other end of the inductor L803, and the other end of the capacitor 803.

[0153] In terms of specific implementation, for the fifth resonance module, the sixth resonance module, the seventh resonance module, and the eighth resonance module, the inductance values of the inductor L503, the inductor L603, the inductor L703, and the inductor L803 are equal, and the same inductor is used; the inductance values of the inductor L503, the inductor L603, the inductor L703, and the inductor L803 are 3.255 nH.

[0154] The capacitance values of the capacitor C503, the capacitor C603, the capacitor C703, and the capacitor C803 are equal, and the same capacitor is used. The capacitance values of the capacitor C503, the capacitor C603, the capacitor C703, and the capacitor C803 are 14.010 pF.

[0155] In terms of specific implementation, for the second coupling module, the inductance values of the inductor L21 and the inductor L23 are equal, and the same inductor is used; the inductance values of the inductor L22 and the inductor L24 are equal, and the same inductor is used.

[0156] The inductance values of the inductor L21 and the inductor L23 are 6.415 nH;

[0157] The inductance values of the inductor L22 and the inductor L24 are 9.245 nH.

[0158] It should be noted that in the second embodiment, Figure 5 the topology of the 90-degree lumped parameter bandpass filter coupler shown mainly includes 4 capacitors and 8 inductors.

[0159] Among them, the inductors L21, L22, L23, and L24 mainly implement the coupling function;

[0160] The inductors L503, L603, L703, L803 and the capacitors C503, C603, C703, C803 mainly implement the filtering function.

[0161] The present invention can control the filtering and coupling performance of the filter coupler, as well as other parameters such as the center frequency, coupling degree, and output phase difference by adjusting the corresponding capacitors and inductors. Port1 is the input port, Port2 and Port3 are the output ports, and Port4 is the isolation port, where the powers of the signals output from Port2 and Port3 are equal and the phase difference is 90 degrees.

[0162] Embodiment Three.

[0163] In the present invention, referring to Figure 6 , when Port1 is the signal input port, the phases of the signals output from Port2 and Port3 differ by 180°, and Port4 is the isolation port, the four resonance modules specifically include the ninth resonance module, the tenth resonance module, the eleventh resonance module, and the twelfth resonance module;

[0164] Among them, the ninth resonance module includes an inductor L903, an inductor L904, and a capacitor C903;

[0165] The inductor L903 is connected in parallel with a series branch composed of the inductor L904 and the capacitor C903;

[0166] One end of the inductor L903 and one end of the inductor L904 are grounded;

[0167] The tenth resonance module includes an inductor L1002, an inductor L1005, and a capacitor C1001;

[0168] The inductor L1002 is connected in parallel with a series branch composed of the inductor L1005 and the capacitor C1001;

[0169] One end of the inductor L1002 and one end of the capacitor C1001 are grounded;

[0170] The eleventh resonance module includes an inductor L1103, an inductor L1104, and a capacitor C1103;

[0171] The inductor L1103 is connected in parallel with a series branch composed of the inductor L1104 and the capacitor C1103;

[0172] One end of the inductor L1103 and one end of the inductor L1104 are grounded;

[0173] The twelfth resonance module includes an inductor L1202, an inductor L1205, and a capacitor C1201;

[0174] The inductor L1202 is connected in parallel with a series branch composed of the inductor L1205 and the capacitor C1201;

[0175] One end of the inductor L1202 and one end of the capacitor C1201 are grounded;

[0176] Among them, the coupling module specifically adopts the third coupling module;

[0177] The third coupling module includes an inductor L31, a capacitor C31, a capacitor C32, and a capacitor C33 connected in sequence;

[0178] Among them, the connection node A3 between the capacitor C31 and the capacitor C32 is respectively connected to the port Port1, the other end of the inductor L903, and one end of the capacitor C903;

[0179] The connection node B3 between the inductor L31 and the capacitor C31 is respectively connected to the port Port2, the other end of the inductor L10023, and one end of the inductor L1005;

[0180] The connection node C3 between capacitor C32 and capacitor C33 is respectively connected to port Port3, the other end of inductor L1103, and one end of capacitor C1103;

[0181] The connection node D3 between capacitor C33 and inductor L31 is respectively connected to port Port4, the other end of inductor L1202, and one end of inductor L1205.

[0182] In terms of specific implementation, for the eleventh resonance module and the twelfth resonance module, the inductance values of inductor L1002 and inductor L1202 are equal, and the same inductor is used. The specific inductance value is L2 = 3.35 nH;

[0183] The inductance values of inductor L1005 and inductor L1205 are equal, and the same inductor is used. The specific inductance value is 10.48 nH;

[0184] The capacitance values of capacitor C1001 and capacitor C1201 are equal, and the same capacitor is used. The specific capacitance value is 1.86 pF.

[0185] In terms of specific implementation, for the ninth resonance module and the eleventh resonance module, the inductance values of inductor L903 and inductor L1103 are equal, and the same inductor is used. The specific inductance value is 1.76 nH;

[0186] The inductance values of inductor L904 and inductor L1104 are equal, and the same inductor is used. The specific inductance value is 7.32 nH;

[0187] The capacitance values of capacitor C903 and capacitor C1103 are equal, and the same capacitor is used. The specific capacitance value is 2.59 pF.

[0188] In terms of specific implementation, for the third coupling module, the capacitance values of capacitor C31, capacitor C32, and capacitor C33 are equal, and the same capacitor is used. The specific capacitance value is 2.316 pF.

[0189] In terms of specific implementation, the inductance value of inductor L31 is 10.95 nH;

[0190] It should be noted that in Embodiment 3, Figure 6This is the schematic diagram of another 180-degree lumped-parameter filter coupler proposed by the present invention. In the figure, the inductor L31 and the capacitors C31, C32, and C33 mainly implement the coupling function, and C1001, C1201, C903, C1103, L1002, L1202, L903, L1103, L904, L1104, L1005, and L1205 mainly implement the filtering function. At these capacitance and inductance parameters, the center frequency at which the filter coupler operates is 1 GHz. Among them, Port1 is the input port, Port2 and Port3 are the output ports, Port4 is the isolation port, and the power of the signals output from Port2 and Port3 is equal and the phase difference is 180 degrees.

[0191] Embodiment 4.

[0192] In the present invention, referring to Figure 7 , when Port1 is the signal input port, the phase difference between the signals output from Port2 and Port3 is 90°, and Port4 is used as the isolation port, the four resonance modules specifically include the thirteenth resonance module, the fourteenth resonance module, the fifteenth resonance module, and the sixteenth resonance module;

[0193] Among them, the thirteenth resonance module includes the inductor L1303 and the capacitor C1303;

[0194] The inductor L1303 and the capacitor C1303 are connected in parallel;

[0195] One end of the inductor L1303 and one end of the capacitor C1303 are grounded;

[0196] The fourteenth resonance module includes the inductor L1403 and the capacitor 1403;

[0197] The inductor L1403 and the capacitor C1403 are connected in parallel;

[0198] One end of the inductor L1403 and one end of the capacitor C1403 are grounded;

[0199] The fifteenth resonance module includes the inductor L1503 and the capacitor C1503;

[0200] The inductor L1503 and the capacitor C1503 are connected in parallel;

[0201] One end of the inductor L1503 and one end of the capacitor C1503 are grounded;

[0202] The sixteenth resonance module includes the inductor L1603 and the capacitor C1603;

[0203] The inductor L1603 and the capacitor C1603 are connected in parallel;

[0204] One end of the inductor L1603 and one end of the capacitor C1603 are grounded;

[0205] Among them, the coupling module specifically adopts the fourth coupling module;

[0206] Among them, the second coupling module includes a capacitor C41, a capacitor C42, a capacitor C43, and a capacitor C44 connected in sequence;

[0207] The connection node A4 between the capacitor C41 and the capacitor C42 is respectively connected to the port Port1, the other end of the inductor L1303, and the other end of the capacitor 1303;

[0208] The connection node B4 between the capacitor C42 and the capacitor C43 is respectively connected to the port Port2, the other end of the inductor L1403, and the other end of the capacitor 1403;

[0209] The connection node C4 between the capacitor C43 and the capacitor C44 is respectively connected to the port Port3, the other end of the inductor L1503, and the other end of the capacitor 1503;

[0210] The connection node D4 between the capacitor C44 and the capacitor C41 is respectively connected to the port Port4, the other end of the inductor L1603, and the other end of the capacitor 1603.

[0211] In specific implementation, for the thirteenth resonance module, the fourteenth resonance module, the fifteenth resonance module, and the sixteenth resonance module, the inductance values of the inductors L1303, L1403, L1503, and L1603 are equal. The same inductor is used, and the inductance value is 0.94 nH;

[0212] The capacitance values of the capacitors C1303, C14603, C1503, and C1603 are equal. The same capacitor is used, and the capacitance value is 20.00 pF.

[0213] In specific implementation, for the fourth coupling module, the capacitance values of the capacitors C41 and C43 are equal, both being 2.82 pF;

[0214] The capacitance values of the capacitors C42 and C44 are equal, both being 4.00 pF.

[0215] It should be noted that in the fourth embodiment, Figure 7This is the schematic diagram of another 90-degree lumped-parameter filter coupler proposed by the present invention. In the figure, capacitors C41, C42, C43, and C44 mainly implement the coupling function, and capacitors C1303, C14603, C1503, and C1603, as well as inductors L1303, L1403, L1503, and L1603 mainly implement the filtering function. At these capacitor and inductor parameters, the center frequency at which the filter coupler operates is 1 GHz. Among them, Port1 is the input port, Port2 and Port3 are the output ports, Port4 is the isolation port, and the powers of the signals output from Port2 and Port3 are equal and the phase difference is 90 degrees.

[0216] It should be noted that the lumped-parameter filter coupler of the present invention can be implemented on a platform of a dielectric integrated suspended line, and the simulation experimental results are in good agreement. This filter coupler can simultaneously achieve band-pass filtering and coupling functions near the center frequency of 1 GHz. It integrates the two functions using lumped-parameter circuits, reducing the circuit size.

[0217] For the present invention, for the coupling function of the filter coupler, a 90-degree coupler or a 180-degree coupler topology is integrated on the filter coupler. If a 90-degree coupling function is to be achieved, the coupler part can adopt a branch-line coupler topology; if a 180-degree coupling function is to be achieved, the coupler part can adopt a Rat-Race coupler topology; for coupling functions with other preset angles, the coupler part can adopt the lumped-parameter topology of the corresponding coupler type. If a filter coupler with different coupling degrees is required, the overall lumped-parameter filter coupler topology can also be improved by setting the corresponding capacitors and inductors or adopting the lumped-parameter topology of the corresponding type of coupler. If a filter coupler with a different center frequency is required, it can be achieved by adjusting the corresponding capacitors and inductors.

[0218] For the present invention, for the filtering function of the filter coupler, if a band-pass filtering function is to be achieved, a parallel resonant circuit can be used and connected in parallel to the four ports to provide the band-pass filtering function, and a series resonance can be used to increase the zeros to improve the filtering performance. Other improved band-pass filters can also be used to achieve the band-pass filtering effect; if a low-pass or high-pass filtering characteristic is to be achieved, a low-pass or high-pass filter can also be integrated into the coupler topology; if a filter coupler with stronger filtering characteristics is to be achieved, a cascaded filter can also be used.

[0219] For the present invention, for the lumped-parameter capacitors and inductors for implementing the filter coupler, the capacitors can adopt single-layer or multi-layer planar capacitors, single-layer or multi-layer interdigital capacitors. If a filter coupler with adjustable coupling degree and filtering performance is to be achieved, a voltage-tunable capacitor can also be used; the inductors can be replaced by a section of microstrip line, strip line, or suspended line, circular and rectangular loop inductors, or single-layer and multi-layer spiral inductors.

[0220] In summary, compared with the prior art, the lumped-parameter filter coupler provided by the present invention is scientifically designed. By using lumped parameters to simultaneously achieve the filtering and coupling functions, it can effectively reduce the size of the circuit and has great practical significance.

[0221] For the lumped-parameter filter coupler of the present invention, it integrates the filtering function and the coupling function, realizing two functions with one circuit, and adopting a lumped-parameter circuit, it is easy to make the size of the circuit very small in the low-frequency band.

[0222] In addition, the lumped-parameter filter coupler provided by the present invention can also adjust the center frequency, coupling degree, coupling bandwidth and output phase of the filter by adjusting the sizes of the lumped-parameter capacitors and inductors of the topology and the topology of the coupler part, having the advantage of flexible design.

[0223] The above are only the preferred embodiments of the present invention. It should be noted that for those of ordinary skill in the art, without departing from the principle of the present invention, several improvements and refinements can be made, and these improvements and refinements should also be regarded as the protection scope of the present invention.

Claims

1. Lumped-parameter filter coupler, characterized in that, it includes port Port1, port Port2, port Port3 and port Port4; Port Port1, port Port2, port Port3 and port Port4 are respectively connected to a resonant module; The four resonant modules are connected to the same coupling module; The resonant module includes at least one inductor and at least one capacitor; The coupling module includes at least one inductor and / or at least one capacitor; When port Port1 is the signal input port, port Port2 and port Port3 are used as co-directional output ports, and port Port4 is used as the isolation port. At this time, the center frequencies of the signals output by port Port2 and port Port3 are both the preset center frequency, and the power is equal and the phase difference is the preset angle; When port Port4 is the signal input port, port Port2 and port Port3 are used as reverse output ports, and port Port1 is used as the isolation port. At this time, the center frequencies of the signals output by port Port2 and port Port3 are both the preset center frequency, and the power is equal and the phase difference is the preset angle.

2. The lumped-parameter filter coupler according to claim 1, characterized in that, When port Port4 is the signal input port, the phase difference between the signals output by port Port2 and port Port3 is 180° and port Port1 is used as the isolation port, the four resonant modules specifically include a first resonant module, a second resonant module, a third resonant module and a fourth resonant module; Among them, the first resonant module includes inductor L102, inductor L104 and capacitor C102; Inductor L102 is connected in parallel with the series branch composed of inductor L104 and capacitor C102; One end of inductor L102 and one end of inductor L104 are grounded; The second resonant module includes inductor L203, inductor L205 and capacitor C203; Inductor L203 is connected in parallel with the series branch composed of inductor L205 and capacitor C203; One end of inductor L203 and one end of capacitor C203 are grounded; The third resonant module includes inductor L302, inductor L304 and capacitor C302; Inductor L302 is connected in parallel with the series branch composed of inductor L304 and capacitor C302; One end of inductor L302 and one end of inductor L304 are grounded; The fourth resonant module includes inductor L403, inductor L405 and capacitor C403; Inductor L403 is connected in parallel with the series branch composed of inductor L405 and capacitor C403; One end of inductor L403 and one end of capacitor C403 are grounded; Among them, the coupling module specifically adopts the first coupling module; The first coupling module includes inductor L11, inductor L12, inductor L13 and capacitor C11 connected in sequence; Among them, the connection node A1 between inductor L11 and inductor L12 is respectively connected to port Port1, the other end of inductor L102 and one end of capacitor C102; The connection node B1 between the inductor L11 and the capacitor C11 is respectively connected to the port Port2, the other end of the inductor L203, and one end of the inductor L205; The connection node C1 between the inductor L12 and the inductor L13 is respectively connected to the port Port3, the other end of the inductor L302, and one end of the capacitor C302; The connection node D1 between the inductor L13 and the capacitor C11 is respectively connected to the port Port4, the other end of the inductor L403, and one end of the inductor L405.

3. The lumped-parameter filter coupler according to claim 2, characterized in that for the first resonance module and the third resonance module, the inductance values of the inductors L102 and L302 are equal, and the same inductor is used; the inductance values of the inductors L104 and L304 are equal, and the same inductor is used; the capacitance values of the capacitors C102 and C302 are equal, and the same capacitor is used.

4. The lumped-parameter filter coupler according to claim 2, characterized in that for the second resonance module and the fourth resonance module, the inductance values of the inductors L203 and L403 are equal, and the same inductor is used; the inductance values of the inductors L205 and L405 are equal, and the same inductor is used; the capacitance values of the capacitors C203 and C403 are equal, and the same capacitor is used.

5. The lumped-parameter filter coupler according to claim 2, characterized in that for the first coupling module, the inductance values of the inductors L11, L12, and L13 are equal, and the same inductor is used.

6. The lumped-parameter filter coupler according to claim 1, characterized in that when the port Port1 is the signal input port, the phases of the signals output from the ports Port2 and Port3 differ by 90° and the port Port4 is used as the isolation port, the four resonance modules specifically include a fifth resonance module, a sixth resonance module, a seventh resonance module, and an eighth resonance module; wherein, the fifth resonance module includes an inductor L503 and a capacitor C503; the inductor L503 and the capacitor C503 are connected in parallel; one end of the inductor L503 and one end of the capacitor C503 are grounded; the sixth resonance module includes an inductor L603 and a capacitor C603; the inductor L603 and the capacitor C603 are connected in parallel; one end of the inductor L603 and one end of the capacitor C603 are grounded; the seventh resonance module includes an inductor L703 and a capacitor C703; the inductor L703 and the capacitor C703 are connected in parallel; one end of the inductor L703 and one end of the capacitor C703 are grounded; the eighth resonance module includes an inductor L803 and a capacitor C803; the inductor L803 and the capacitor C803 are connected in parallel; one end of the inductor L803 and one end of the capacitor C803 are grounded; wherein, the coupling module specifically adopts a second coupling module; wherein, the second coupling module includes inductors L21, L22, L23, and L24 connected in sequence; the connection node A2 between the inductor L21 and the inductor L24 is respectively connected to the port Port1, the other end of the inductor L503, and the other end of the capacitor 503; The connection node B2 between inductor L21 and inductor L22 is respectively connected to port Port2, the other end of inductor L603, and the other end of capacitor 603; The connection node C2 between inductor L22 and inductor L23 is respectively connected to port Port3, the other end of inductor L703, and the other end of capacitor 703; The connection node D2 between inductor L23 and inductor L24 is respectively connected to port Port4, the other end of inductor L803, and the other end of capacitor 803.

7. The lumped parameter filter coupler according to claim 6, characterized in that for the fifth resonance module, the sixth resonance module, the seventh resonance module, and the eighth resonance module, the inductance values of inductors L503, L603, L703, and L803 are equal, and the same inductor is used; the capacitance values of capacitors C503, C603, C703, and C803 are equal, and the same capacitor is used.

8. The lumped parameter filter coupler according to claim 6, characterized in that for the second coupling module, the inductance values of inductors L21 and L23 are equal, and the same inductor is used; the inductance values of inductors L22 and L24 are equal, and the same inductor is used.

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