A power distribution circuit and a differential power distributor with filtering function

Abstract

The application discloses a power distribution circuit and a differential power distributor with a filtering function. The power distribution circuit comprises a pair of differential input ports, two pairs of differential output ports, four coupled microstrip line structures, four terminal open-circuit stepped impedance stubs, two lumped parameter isolation resistors, two microstrip lines and four lambda / 4 impedance transformation lines. The differential power distributor comprises a dielectric plate and a power distribution circuit carried on the front surface of the dielectric plate, and a metal ground surface is arranged on the back surface of the dielectric plate. The differential power distributor of the application simultaneously realizes the functions of signal filtering and power distribution, can effectively improve electromagnetic interference suppression, suppresses common-mode signals caused by power supply and ground conductors, realizes a relatively wide passband, has relatively high selectivity and has good popularization prospects.

Description

Technical Field

[0001] This invention relates to the field of microwave transmission technology, specifically to a power distribution circuit and a differential power divider with filtering function. Background Technology

[0002] Power dividers are commonly used passive microwave devices in many commercial and industrial electronic systems, widely applied in microwave circuits such as power amplifiers, mixers, antenna arrays, and frequency multipliers. Meanwhile, in active circuits or antenna arrays, bandpass filters are typically cascaded before or after the power divider to filter out out-of-band interference or harmonics and intermodulation signals generated by the active devices. Traditional microstrip line filters are complex in structure, require significant space, and exhibit insertion loss. Therefore, implementing filtering microwave devices through direct filter cascading is insufficient to meet the miniaturization requirements of communication systems and further increases the system's insertion loss, thus impacting the overall system performance.

[0003] With the rapid development of highly integrated and low-cost communication systems, it is necessary to consider minimizing size and increasing functional integration when designing equipment. One effective method is to integrate a power divider and a bandpass filter into a single component, i.e., a power divider with filtering capabilities. Furthermore, differential power dividers offer superior common-mode signal rejection performance compared to conventional single-ended power dividers, improving the communication system's immunity to environmental noise. As one of the most fundamental components in building wireless communication systems, differential power dividers are indispensable when constructing balanced systems. Generally, there are two types of differential power dividers: single-ended to differential (or differential to single-ended) power dividers and differential to differential power dividers. Of these two types, only differential to differential power dividers can construct a fully balanced RF front-end. The core of implementing a differential to differential power divider is to suppress common-mode signals (reflection or absorption) while maintaining low loss and efficient power distribution for differential signals.

[0004] Taking into account the requirements of balanced RF front-end for power distribution, filtering characteristics, and integration, this invention proposes a differential-to-differential power divider with filtering function. Compared with the prior art, the differential power divider proposed in this invention has superior common-mode signal suppression performance, low differential-mode signal transmission loss, and high bandpass filtering characteristics, which can filter out interference frequency signals while distributing differential signal power. Summary of the Invention

[0005] The purpose of this invention is to address the problems existing in the prior art by providing a power distribution circuit and a differential power divider with filtering function. By integrating filtering characteristics into the power divider, a single multi-functional device with both signal filtering and power distribution functions, namely a filtered power divider, is realized; at the same time, the differential structure can effectively suppress common-mode signals.

[0006] To address the shortcomings of the aforementioned technical problems, the present invention provides a power distribution circuit, comprising:

[0007] A pair of differential input ports, located at the left and right ends of the circuit, are used to input differential signals;

[0008] Two pairs of differential output ports are located at the top and bottom of the circuit, used to output differential signals with the same amplitude and phase;

[0009] Four coupled microstrip line structures with circuit parameters Z e1 Z o1 θ1;

[0010] Four open-ended stepped impedance stubs;

[0011] Two lumped-parameter isolation resistors have circuit parameters (R);

[0012] Two microstrip lines with circuit parameters (Z2, θ3) are located at the center of the circuit.

[0013] Four λ / 4 impedance transformation lines with circuit parameters (Z1, θ2) are used to pre-transform the output port impedance.

[0014] The circuit's quarter-section structure consists of a coupled microstrip line structure. One end of the microstrip line is connected to the differential input port, and the other end is connected to the microstrip line and an isolation resistor connected in parallel with it. The other microstrip line is open at one end and connected to a stepped impedance stub consisting of the microstrip line and an open-ended terminal, and a λ / 4 impedance transformation line connected in parallel with it. The other end of the λ / 4 impedance transformation line is connected to the differential output port. The rest of the circuit is symmetrical to this structure and is connected vertically by isolation resistors and horizontally by microstrip lines.

[0015] As a further optimization of the power distribution circuit of the present invention: the four open-ended stepped impedance stubs are each formed by two microstrip lines connected in series, the circuit parameters of the first microstrip line are (Z3, θ4), and the circuit parameters of the second microstrip line are (Z4, θ5) with the end open.

[0016] As a further optimization of the power distribution circuit of the present invention: each of the four coupled microstrip line structures is composed of a pair of parallel microstrip lines.

[0017] As a further optimization of the power distribution circuit of the present invention: the differential input ports and the two differential output ports all have a differential mode impedance of 100 Ohm and a common mode impedance of 25 Ohm.

[0018] As a further optimization of the power distribution circuit of the present invention: the electrical length is

[0019] As a further optimization of the power distribution circuit of the present invention, the circuit parameters satisfy the following formula:

[0020]

[0021] A differential power divider with filtering function includes a dielectric substrate and a power distribution circuit carried on the front side of the dielectric substrate, and a metal ground plane is provided on the back side of the dielectric substrate.

[0022] The power distribution circuit includes:

[0023] A pair of differential input ports, located at the left and right ends of the circuit, are used to input differential signals;

[0024] Two pairs of differential output ports are located at the top and bottom of the circuit, used to output differential signals with the same amplitude and phase;

[0025] Four coupled microstrip line structures with circuit parameters Z e1 Z o1 θ1;

[0026] Four open-ended stepped impedance stubs;

[0027] Two lumped-parameter isolation resistors have circuit parameters (R);

[0028] Two microstrip lines with circuit parameters (Z2, θ3) are located at the center of the circuit.

[0029] Four λ / 4 impedance transformation lines with circuit parameters (Z1, θ2) are used to pre-transform the output port impedance.

[0030] The circuit's quarter-section structure consists of a coupled microstrip line structure. One end of the microstrip line is connected to the differential input port, and the other end is connected to the microstrip line and an isolation resistor connected in parallel with it. The other microstrip line is open at one end and connected to a stepped impedance stub consisting of the microstrip line and an open-ended terminal, and a λ / 4 impedance transformation line connected in parallel with it. The other end of the λ / 4 impedance transformation line is connected to the differential output port. The rest of the circuit is symmetrical to this structure and is connected vertically by isolation resistors and horizontally by microstrip lines.

[0031] As a further optimization of the differential power divider with filtering function of the present invention: the operating center frequency of the power divider is [value], and it has two transmission zeros within DC [range]. The calculation formula is as follows:

[0032]

[0033] The present invention has the following beneficial effects:

[0034] (1) The power distribution circuit of the present invention has a simple, symmetrical, compact and practical structure;

[0035] (2) The power distribution circuit of the present invention has a differential structure, which can effectively improve electromagnetic interference suppression and suppress common-mode signals caused by power supply and grounding conductor;

[0036] (3) The differential power divider of the present invention has a filtering function, realizes a wide passband, has high selectivity, and has good prospects for promotion. Attached Figure Description

[0037] Figure 1 This is a schematic diagram of the power divider circuit of the present invention;

[0038] Figure 2 This is a schematic diagram of the power divider circuit of the present invention;

[0039] Figure 3 Simulation of the power divider circuit of this invention (S) ddAA S ddBA S ddBB S ddBC Parameter diagram;

[0040] Figure 4 Simulation of the power divider circuit of this invention (S) ccAA S ccBA S ccBB S ccBC Parameter diagram. Detailed Implementation

[0041] To better understand the present invention, the following embodiments further illustrate the content of the present invention, but the content of the present invention is not limited to the following embodiments.

[0042] <Power Divider Circuit>

[0043] like Figure 1 The diagram shown is a circuit diagram of the present invention. The power distribution circuit includes:

[0044] A pair of differential input ports are located at the left and right ends of the circuit for inputting differential signals. There are one pair of differential input ports and two pairs of differential output ports. The differential-mode impedance is 100 Ohm and the common-mode impedance is 25 Ohm.

[0045] Two pairs of differential output ports are located at the top and bottom of the circuit, used to output differential signals with the same amplitude and phase;

[0046] Four coupled microstrip line structures, with circuit parameters Z e1 Z o1 The four coupled microstrip line structures, θ1 and θ2, are each composed of a pair of parallel microstrip lines.

[0047] The four open-ended stepped impedance stubs are each formed by two microstrip lines connected in series. The circuit parameters of the first microstrip line are (Z3, θ4), and the circuit parameters of the second microstrip line are (Z4, θ5).

[0048] Two lumped-parameter isolation resistors have circuit parameters (R);

[0049] Two microstrip lines with circuit parameters (Z2, θ3) are located at the center of the circuit.

[0050] Four λ / 4 impedance transformation lines with circuit parameters (Z1, θ2) are used to pre-transform the output port impedance.

[0051] Wherein, the electric length is

[0052] The circuit's quarter-section structure consists of a coupled microstrip line structure. One end of the microstrip line is connected to the differential input port, and the other end is connected to the microstrip line and an isolation resistor connected in parallel with it. The other microstrip line is open at one end and connected to a stepped impedance stub consisting of the microstrip line and an open-ended terminal, and a λ / 4 impedance transformation line connected in parallel with it. The other end of the λ / 4 impedance transformation line is connected to the differential output port. The rest of the circuit is symmetrical to this structure and is connected vertically by isolation resistors and horizontally by microstrip lines.

[0053] The circuit parameters satisfy the following formula:

[0054]

[0055] In this embodiment, the circuit parameters are: Z e1 =140 Ohm, Z o1 =60.0Ohm, θ1=90°, Z3=19.0Ohm, θ4=90°, Z4=95.0Ohm, θ5=90°, Z1=25.0Ohm, θ2=90°, Z2=22.6Ohm, θ3=180°, R=90.0Ohm.

[0056] like Figure 2 The diagram shows the structure of the power divider of the present invention:

[0057] The length and width of one pair of differential input ports and two pairs of differential output ports are L1 = 5.00 mm and W1 = 1.55 mm, respectively; the length, width, and spacing of the four pairs of coupled microstrip lines are L2 = 27.00 mm, W2 = 0.40 mm, and S1 = 0.10 mm, respectively; the length and width of the first microstrip line of the stepped impedance stub with open-circuit termination are L4 = 24.00 mm and W4 = 5.50 mm, respectively, and the length and width of the second microstrip line are L5 = 26.90 mm and W5 = 0.50 mm, respectively; the length and width of the two microstrip lines in the middle of the circuit are L3 = 49.10 mm and W3 = 4.50 mm, respectively, and the spacing between the two lines is S2 = 1.85 mm.

[0058] Differential broadband power divider with filtering function

[0059] A differential power divider with filtering function includes a dielectric substrate and a power distribution circuit carried on the front side of the substrate, with a metal ground plane on the back side of the substrate. The dielectric substrate has a thickness of 0.508 mm and a dielectric constant of 2.2. The power distribution circuit adopts the aforementioned <Power Divider Circuit>.

[0060] In this embodiment, the filter power divider operates over a wide bandwidth of 1.78 to 2.35 GHz, with a differential-mode input reflection coefficient S. ddAA Less than -10dB, with a relative bandwidth of 28.5%. Differential mode output reflection coefficient S over a wide bandwidth from 1.83 to 2.32 GHz. ddBB (S ddCC The differential mode transfer factor (S) is greater than -10dB, with a relative bandwidth of 24.5%. ddBA (S ddCA The isolation value (S) between the differential output ports is located between -3.2dB and -3.3dB. ddBC The value is less than -13dB, indicating that it can achieve good isolation within the passband and has the function of broadband bandpass filtering. In addition, this coupled-line power divider achieves a wide stopband between 2.47GHz and 5.00GHz, and the harmonic suppression is greater than 20dB.

[0061] Figure 4 As shown, the preferred example of the filter power divider has a common-mode input reflection coefficient S over a wide bandwidth from 0 to 5.00 GHz. ccAA and common-mode output reflection coefficient (S ccBA (S ccCA The common-mode rejection ratio (SMRR) is close to 0dB, indicating that the circuit has strong common-mode rejection capability. Furthermore, the isolation value between the common-mode output ports (S) is close to 0dB. ccBC The value is less than -30dB, indicating that the common-mode output achieves excellent isolation.

[0062] The power divider of this invention, through the use of a coupled microstrip line structure circuit, is simple, symmetrical, compact, and practical. It can effectively improve electromagnetic interference suppression, suppress common-mode signals caused by power supply and ground conductors, achieve a wide passband, have high selectivity, and has good prospects for widespread application.

[0063] The specific embodiments of the present invention have been described above. It should be understood that the present invention is not limited to the specific embodiments described above, and those skilled in the art can make various modifications or variations within the scope of the claims, which do not affect the essence of the present invention.

Claims

1. A power distribution circuit, characterized in that, include: A pair of differential input ports, located at the left and right ends of the circuit, are used to input differential signals; Two pairs of differential output ports are located at the top and bottom of the circuit, used to output differential signals with the same amplitude and phase; Four coupled microstrip line structures, with the following circuit parameters: ; Four open-ended stepped impedance stubs; Two lumped-parameter isolation resistors, with circuit parameters R; Two microstrip lines, their circuit parameters are as follows It is located at the center of the circuit; Four λ / 4 impedance transformation lines, with the following circuit parameters: This is used to pre-transform the output port impedance; The power distribution circuit is divided into four symmetrical parts by the horizontal and vertical axes passing through the midpoint of the power distribution circuit. The circuit's quarter structure is a microstrip line structure in which one end of the microstrip line is connected to the differential input port, and the other end is connected to the microstrip line and the isolation resistor connected in parallel with it. One end of the other microstrip line coupled to the microstrip line is open, and the other end is connected to the stepped impedance stub with the open terminal and the λ / 4 impedance transformation line connected in parallel. The other end of the λ / 4 impedance transformation line is connected to the differential output port. The remaining three-quarters of the power distribution circuit are obtained by mirroring this quarter structure about the horizontal and vertical axes respectively, and are connected vertically by isolation resistors and horizontally by microstrip lines.

2. The power distribution circuit as described in claim 1, characterized in that, Each of the four open-ended stepped impedance stubs is formed by two microstrip lines connected in series, and the circuit parameters of the first microstrip line are as follows: The second microstrip line is open-circuited at its end, and its circuit parameters are as follows: .

3. The power distribution circuit as described in claim 1, characterized in that, Each of the four coupled microstrip line structures consists of a pair of parallel microstrip lines.

4. The power distribution circuit as described in claim 1, characterized in that, The differential input ports and the two differential output ports each have a differential-mode impedance of 100 Ohm and a common-mode impedance of 25 Ohm.

5. The power distribution circuit as described in claim 2, characterized in that: Electric length is .

6. The power distribution circuit as described in claim 2, characterized in that: The circuit parameters satisfy the following formula: 。 7. A differential power divider with filtering function, characterized in that, It includes a dielectric substrate and a power distribution circuit carried on the front side of the dielectric substrate, and a metal ground plane is provided on the back side of the dielectric substrate; The power distribution circuit includes: A pair of differential input ports, located at the left and right ends of the circuit, are used to input differential signals; Two pairs of differential output ports are located at the top and bottom of the circuit, used to output differential signals with the same amplitude and phase; Four coupled microstrip line structures, with the following circuit parameters: ; The four open-ended stepped impedance stubs are each formed by two microstrip lines connected in series. The circuit parameters of the first microstrip line are as follows: The second microstrip line is open-circuited at its end, and its circuit parameters are as follows: ; Two lumped-parameter isolation resistors, with circuit parameters R; Two microstrip lines, their circuit parameters are as follows It is located at the center of the circuit; Four λ / 4 impedance transformation lines, with the following circuit parameters: This is used to pre-transform the output port impedance; The power distribution circuit is divided into four symmetrical parts by the horizontal and vertical axes passing through the midpoint of the circuit. The quarter-section structure consists of one microstrip line in the coupled microstrip line structure, with one end connected to the differential input port and the other end connected to the microstrip line and the isolation resistor connected in parallel. The other microstrip line is open at one end and connected to a stepped impedance stub with an open terminal and a λ / 4 impedance transformation line connected in parallel. The other end of the λ / 4 impedance transformation line is connected to the differential output port. The remaining three-quarters of the power distribution circuit are obtained by mirroring this quarter-section structure symmetrically about the horizontal and vertical axes, and are connected vertically by the isolation resistor and horizontally by the microstrip line.

8. The differential power divider with filtering function as described in claim 7, characterized in that: The operating center frequency of the power divider is Its DC to It has two transmission zeros, and the calculation formula is as follows: ； 。

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