Wilkinson power divider with common ground capacitor structure

Abstract

The invention discloses a Wilkinson power divider with a common ground capacitor structure. The Wilkinson power divider comprises an input port Port1; the output ports comprise a Port 2 and a Port 3; the series inductor comprises L2, L3, L4 and L5; the shunt capacitor comprises C1, C2, C3 and C4; the isolation resistor comprises R1 and R2; wherein the capacitor C1 and the capacitor C2 are connected to form a common ground capacitor, and the capacitor C3 and the capacitor C4 are connected to form a common ground capacitor; the common ground capacitor and the isolation resistor are very close to each other in a physical layout, are matched and isolated together and act together to improve the isolation degree, meanwhile, the inductance value and the capacitance value of the inductor are optimized to reduce the needed inductance, elements such as a ground hole and a matching capacitor C1 are removed, the circuit area is greatly reduced, and the cost is reduced. The number of circuit components, especially the number of ground holes, is reduced, multi-stage isolation of the Wilkinson power divider is achieved in a smaller area, and the performance such as isolation is greatly improved.

Description

Technical Field

[0001] The invention relates to the technical field of communication systems, and in particular to a Wilkinson power divider with a common ground capacitor structure. Background Art

[0002] The background technology of Wilkinson power divider involves microwave circuit design and signal distribution problems. With the complexity of communication systems and the expansion of frequency range, the demand for technology that can efficiently and accurately distribute and synthesize signals is growing. Key technologies such as signal distribution requirements, isolation, matching networks, passive components, transmission line technology and impedance transformation are particularly important in microwave circuit design. Wilkinson power divider uses transmission lines and resistors to achieve equal distribution and high isolation of signals. It consists of an input port, two output ports, a center resistor and a quarter-wavelength transmission line, which solves the challenge of signal distribution at microwave frequencies. It has a simple design and stable performance and has been widely used in microwave engineering.

[0003] In the existing technology, the classic Wilkinson power divider has a large structure and is difficult to meet the requirements of broadband and miniaturization. To solve this problem, engineers use capacitive load method and lumped component replacement method, but the traditional broadband lumped Wilkinson power divider structure has the following disadvantages: the capacitor-to-ground structure is difficult to implement, which increases the area and deteriorates the symmetry; the ground via brings parasitic inductance, affecting the working bandwidth; the ground via area is larger than the capacitor, which increases the power divider area. Summary of the invention

[0004] The object of the present invention is to provide a Wilkinson power divider with a common ground capacitor structure to solve the problems raised in the above background technology.

[0005] To achieve the above object, the present invention provides the following technical solution: a Wilkinson power divider with a common ground capacitor structure, comprising:

[0006] Input port Port1;

[0007] Output port Port2 and output port Port3;

[0008] The series inductors include: L2, L3, L4, L5;

[0009] The parallel capacitors include: C1, C2, C3, C4;

[0010] Isolation resistors include: R1, R2;

[0011] Wherein, capacitor C1 and capacitor C2 are connected to form a first common ground capacitor, and capacitor C3 and capacitor C4 are connected to form a second common ground capacitor;

[0012] The isolation resistor R1 is arranged between the first common ground capacitor and the second common ground capacitor;

[0013] The isolation resistor R2 is arranged between the output port Port2 and the output port Port3;

[0014] The isolation resistors are respectively connected between the input port Port1 and the output port Port2, and between the input port Port1 and the output port Port3;

[0015] The parallel capacitors are connected between Port1 and Port2, and between Port1 and Port3, respectively, and the connection terminals of the parallel capacitors are adjacent to the connection terminals of the isolation resistors;

[0016] The series inductor is connected between Port1 and Port2, and between Port1 and Port3, respectively, and a connection end point of the series inductor is adjacent to a connection end point of the parallel capacitor;

[0017] The connection end of the parallel capacitor is not directly connected to the ground, but is connected to the ground through an isolation resistor to form a common ground connection.

[0018] Preferably, the isolation resistor and the capacitor together constitute a π-type circuit structure, and the resistance value of the isolation resistor and the capacitance value of the capacitor are designed so that the characteristic impedance of the π-type circuit structure matches the transmission line characteristic impedance of the Wilkinson power divider. The Wilkinson power divider includes at least two π-type circuit structures, which are respectively connected between the input port Port1 and the output port Port2, and between the input port Port1 and the output port Port3.

[0019] Preferably, the lengths of the inductors L2, L3, L4, and L5 are shorter than the length of a microstrip line in a classic Wilkinson power divider, and the length of the microstrip line in the classic Wilkinson power divider is one quarter wavelength (λ / 4).

[0020] Preferably, the capacitance of the capacitors C1, C2, C3, and C4 is smaller than the capacitance of the matching capacitor in the classic Wilkinson power divider, and the calculation formula of the capacitance value is: in:

[0021] C is the required capacitance value (in farads);

[0022] f is the operating frequency of the power divider (Hz);

[0023] Z0 is the characteristic impedance (ohms).

[0024] Preferably, the resistance values ​​of the isolation resistors R1 and R2 are selected according to the required isolation degree.

[0025] Preferably, the capacitors C1 and C2, and the capacitors C3 and C4 are connected in a straight-through manner.

[0026] Preferably, the capacitors C1 and C2, and C3 and C4 are connected indirectly via inductors or transmission lines.

[0027] Preferably, the inductors L2, L3, L4, L5 and the capacitors C1, C2, C3, C4 are implemented in the form of microstrip lines, and the series inductors are connected between the connection points of the two π-type circuit structures.

[0028] Preferably, the inductors L2, L3, L4, L5 and the capacitors C1, C2, C3, C4 are implemented in the form of lumped components, the series inductors are spiral inductors, and the parallel capacitors are MIM capacitors.

[0029] Preferably, the isolation resistors R1 and R2 and the common ground capacitors C1 and C2, C3 and C4 are integrated on the same circuit board, and the isolation resistors are thin film resistors.

[0030] The present invention has at least the following beneficial effects:

[0031] 1. When the present invention is in use, the entire Wilkinson power divider has no ground hole and grounding part, and is completely independent from the outside world, so it can be free from the influence of external interference signals. The common ground capacitor and the isolation resistor are very close in the physical layout, and they jointly adjust the matching and isolation, and work together to improve the isolation. At the same time, optimizing the inductance value and the capacitance value can reduce the required inductance size, and removing the ground hole, matching capacitor and other components, greatly reducing the circuit area, reducing the number of circuit components, especially the number of ground holes, enhancing the robustness of the circuit, and improving the tolerance to the inconsistency of the manufacturing process. The multi-level isolation of the Wilkinson power divider is achieved in a smaller area, which greatly improves the isolation performance.

[0032] 2. The present invention sets a Wilkinson power divider with a common ground capacitor structure, removes the ground hole and the grounding part, avoids parasitic inductance, reduces external interference coupling, improves anti-interference ability, and stably works in a complex electromagnetic environment to have strong anti-interference ability. The common ground capacitor simplifies circuit design, reduces the number of components, significantly reduces circuit area, reduces manufacturing costs, and facilitates integration, so that the device has the advantages of small size and low cost. The lumped element technology optimizes the circuit design, improves robustness, and tolerates manufacturing process inconsistencies. Multi-level isolation improves isolation and bandwidth to meet high-performance application requirements, thereby improving the robustness and performance of the device. BRIEF DESCRIPTION OF THE DRAWINGS

[0033] Figure 1 This is a schematic diagram of the structure of the improved broadband lumped Wilkinson power divider of the present invention;

[0034] Figure 2 The second schematic diagram of the structure of the improved broadband lumped Wilkinson power divider of the present invention;

[0035] Figure 3 A schematic diagram showing the comparison of isolation results of the conventional Wilkinson power divider and the new structure of the present invention;

[0036] Figure 4 This is one of the schematic diagrams of the structure of the conventional broadband lumped Wilkinson power divider of the present invention;

[0037] Figure 5 This is the second schematic diagram of the structure of the conventional broadband lumped Wilkinson power divider of the present invention;

[0038] Figure 6 It is a schematic diagram of the structure of the classic Wilkinson power divider of the present invention. DETAILED DESCRIPTION

[0039] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0040] See also Figure 1-6

[0041] Embodiment 1

[0042] A Wilkinson power divider with a common ground capacitor structure, comprising:

[0043] Input port Port1;

[0044] Output port Port2 and output port Port3;

[0045] The series inductors include: L2, L3, L4, L5;

[0046] The parallel capacitors include: C1, C2, C3, C4;

[0047] Isolation resistors include: R1, R2;

[0048] Wherein, capacitor C1 and capacitor C2 are connected to form a first common ground capacitor, and capacitor C3 and capacitor C4 are connected to form a second common ground capacitor;

[0049] The isolation resistor R1 is arranged between the first common ground capacitor and the second common ground capacitor;

[0050] The isolation resistor R2 is arranged between the output port Port2 and the output port Port3;

[0051] The isolation resistors are respectively connected between the input port Port1 and the output port Port2, and between the input port Port1 and the output port Port3;

[0052] The parallel capacitors are connected between Port1 and Port2, and between Port1 and Port3, respectively, and the connection terminals of the parallel capacitors are adjacent to the connection terminals of the isolation resistors;

[0053] The series inductor is connected between Port1 and Port2, and between Port1 and Port3, respectively, and a connection end point of the series inductor is adjacent to a connection end point of the parallel capacitor;

[0054] The connection end of the parallel capacitor is not directly connected to the ground, but is connected to the ground through an isolation resistor to form a common ground connection.

[0055] This embodiment uses microstrip line technology to implement the circuit elements of the Wilkinson power divider. The series inductors L2-L5 and the parallel capacitors C1-C4 are all made in the form of microstrip lines, and the required inductance and capacitance values ​​are formed by etching. The common ground capacitors C1 and C2, and the connection points of C3 and C4 are respectively connected to the isolation resistors R1 and R2 to form a common ground structure. The isolation resistors R1 and R2 are also implemented using microstrip line technology, and the required isolation degree is achieved by adjusting their resistance values.

[0056] Specific implementation process: First, according to the design requirements, select appropriate microstrip line parameters, make input port Port1, output ports Port2 and Port3, and series inductors L2, L3, L4, L5, then make parallel capacitors C1, C2, C3, C4, and connect C1 with C2, C3 with C4 respectively to form a common ground capacitor, then connect the isolation resistor R1 between the connection point of C1 and C2 and the connection point of C3 and C4, connect the isolation resistor R2 between the output ports Port2 and Port3, connect at least two isolation resistors, two parallel capacitors and two series inductors between Port1 and Port2, and between Port1 and Port3 respectively, ensure that the connection end point of the parallel capacitor is adjacent to the connection end point of the isolation resistor, and the connection end point of the series inductor is adjacent to the connection end point of the parallel capacitor, and use microstrip line technology to implement The above-mentioned circuit elements are present, and the required inductance and capacitance values ​​are formed by an etching process. In Example 2, multiple π-type circuit structures are added, including isolation resistors R4, R5 and common ground capacitors C6, C7, C8, and C9, to achieve wider bandwidth and higher isolation. In Example 3, the length of the series inductor and the capacitance of the parallel capacitor are reduced, and the common ground capacitor and the isolation resistor are integrated on the same circuit board to improve the integration. In Example 4, a first-level isolation circuit is added, including an isolation resistor R3 and a common ground capacitor C5, to achieve higher isolation. In Example 5, the circuit elements are realized by lumped element technology, the series inductor adopts a spiral inductor, the parallel capacitor adopts a MIM capacitor, and the isolation resistor adopts a thin film resistor. The required isolation is achieved by adjusting the resistance value of the isolation resistor. Finally, the performance test of the entire Wilkinson power divider is performed to ensure that the design requirements are met.

[0057] Embodiment 2

[0058] Based on Example 1: the isolation resistor and the parallel capacitor together constitute a π-type circuit structure, the resistance value of the isolation resistor and the capacitance value of the parallel capacitor are designed so that the characteristic impedance of the π-type circuit structure matches the transmission line characteristic impedance of the Wilkinson power divider, and the Wilkinson power divider includes at least two π-type circuit structures, which are respectively connected between Port1 and Port2 and between Port1 and Port3. This embodiment adds multiple π-type circuit structures on the basis of Example 2 to achieve wider bandwidth and higher isolation, and adds a π-type circuit structure between the input port Port1 and the output port Port2, including an isolation resistor R4 and two common ground capacitors C6 and C7, and adds a π-type circuit structure between the input port Port1 and the output port Port3, including an isolation resistor R5 and two common ground capacitors C8 and C9. Through the design of multi-stage π-type circuits, this embodiment can achieve wider bandwidth and higher isolation, and further improve performance;

[0059] Embodiment 3

[0060] Based on the first embodiment: the length of the series inductors L2, L3, L4, and L5 is less than the length of the microstrip line in the classic Wilkinson power divider, the capacitance of the parallel capacitors C1, C2, C3, and C4 is less than the capacitance of the matching capacitor in the classic Wilkinson power divider, and the resistance of the isolation resistors R1 and R2 is selected according to the required isolation. This embodiment integrates the common ground capacitors and the isolation resistors on the same circuit board to further reduce the circuit area and improve the integration. The common ground capacitors C1-C4 and the isolation resistors R1-R2 are all made of thin film technology and directly integrated on the circuit board. Through the integrated design, this embodiment can significantly reduce the circuit area and reduce the manufacturing cost while maintaining good performance;

[0061] Embodiment 4

[0062] Based on Example 1: the connection mode of the common ground capacitors C1 and C2, C3 and C4 is direct connection, and the connection mode of the common ground capacitors C1 and C2, C3 and C4 is indirect connection, connected through inductance or transmission line. This embodiment adds a first-level isolation circuit on the basis of Example 1 to achieve higher isolation, and adds an isolation resistor R3 and a common ground capacitor C5 between the output ports Port2 and Port3 to form a second-level isolation circuit. The first-level isolation circuit is composed of R1 and the common ground capacitors C1-C2, and the second-level isolation circuit is composed of R2 and the common ground capacitors C3-C4. Through the design of the two-stage isolation circuit, this embodiment can achieve higher isolation and further reduce the impact of external interference;

[0063] Embodiment 5

[0064] Based on Example 1: the series inductors L2, L3, L4, L5 and the parallel capacitors C1, C2, C3, C4 are implemented in the form of microstrip lines, the series inductors are connected between the connection points of the two π-type circuit structures, the series inductors L2, L3, L4, L5 and the parallel capacitors C1, C2, C3, C4 are implemented in the form of lumped components, the series inductors are spiral inductors, the parallel capacitors are MIM capacitors, the isolation resistors R1, R2 and the common ground capacitors C1 and C2, C3 and C4 are integrated on the same circuit board, the isolation resistors are thin film resistors, this embodiment uses lumped component technology to implement the circuit elements of the Wilkinson power divider, the series inductors L2-L5 are spiral inductors, the parallel capacitors C1-C4 are MIM capacitors, the common ground capacitors C1 and C2, and the connection points of C3 and C4 are respectively connected to the isolation resistors R1 and R2 to form a common ground structure, the isolation resistors R1 and R2 are thin film resistors, and the required isolation is achieved by adjusting their resistance values.

[0065] It should be noted that, in this article, relational terms such as first and second, etc. are only used to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Moreover, the terms "include", "comprise" or any other variants thereof are intended to cover non-exclusive inclusion, so that a process, method, article or device including a series of elements includes not only those elements, but also other elements not explicitly listed, or also includes elements inherent to such process, method, article or device.

[0066] Although embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that various changes, modifications, substitutions and variations may be made to the embodiments without departing from the principles and spirit of the present invention, and that the scope of the present invention is defined by the appended claims and their equivalents.

Claims

1. A Wilkinson power divider with a common ground capacitor structure, characterized in that: include: Input port Port1; Output port Port2 and output port Port3; The series inductors include: L2, L3, L4, L5; The parallel capacitors include: C1, C2, C3, C4; Isolation resistors include: R1, R2; Wherein, capacitor C1 and capacitor C2 are connected to form a first common ground capacitor, and capacitor C3 and capacitor C4 are connected to form a second common ground capacitor; The isolation resistor R1 is arranged between the first common ground capacitor and the second common ground capacitor; The isolation resistor R2 is arranged between the output port Port2 and the output port Port3; The isolation resistors are respectively connected between the input port Port1 and the output port Port2, and between the input port Port1 and the output port Port3; The parallel capacitors are connected between Port1 and Port2, and between Port1 and Port3, respectively, and the connection terminals of the parallel capacitors are adjacent to the connection terminals of the isolation resistors; The series inductor is connected between Port1 and Port2, and between Port1 and Port3, respectively, and a connection end point of the series inductor is adjacent to a connection end point of the parallel capacitor; The connection end of the parallel capacitor is not directly connected to the ground, but is connected to the ground through an isolation resistor to form a common ground connection.

2. The Wilkinson power divider with a common ground capacitor structure according to claim 1, characterized in that: The isolation resistor and the capacitor together form a π-type circuit structure. The resistance value of the isolation resistor and the capacitance value of the capacitor are designed so that the characteristic impedance of the π-type circuit structure matches the transmission line characteristic impedance of the Wilkinson power divider. The Wilkinson power divider includes at least two π-type circuit structures, which are respectively connected between the input port Port1 and the output port Port2, and between the input port Port1 and the output port Port3.

3. The Wilkinson power divider with a common ground capacitor structure according to claim 1, characterized in that: The lengths of the inductors L2, L3, L4, and L5 are shorter than the length of the microstrip line in a classic Wilkinson power divider, where the length of the microstrip line in the classic Wilkinson power divider is a quarter wavelength (λ / 4).

4. The Wilkinson power divider with a common ground capacitor structure according to claim 1, characterized in that: The capacitance of the capacitors C1, C2, C3, and C4 is smaller than the capacitance of the matching capacitor in the classic Wilkinson power divider, and the calculation formula of the capacitance value is: in: C is the required capacitance value (in farads); f is the operating frequency of the power divider (Hz); Z0 is the characteristic impedance (ohms).

5. The Wilkinson power divider with a common ground capacitor structure according to claim 1, characterized in that: The resistance values ​​of the isolation resistors R1 and R2 are selected according to the required isolation degree.

6. The Wilkinson power divider with a common ground capacitor structure according to claim 1, characterized in that: The connection mode of capacitors C1 and C2, and capacitors C3 and C4 is through connection.

7. The Wilkinson power divider with a common ground capacitor structure according to claim 1, characterized in that: The connection mode of capacitors C1 and C2, and capacitors C3 and C4 is indirect connection, which is connected through inductance or transmission lines.

8. The Wilkinson power divider with a common ground capacitor structure according to claim 1, characterized in that: The inductors L2, L3, L4, L5 and the capacitors C1, C2, C3, C4 are implemented in the form of microstrip lines, and the series inductors are connected between the connection points of two π-type circuit structures.

9. The Wilkinson power divider with a common ground capacitor structure according to claim 1, characterized in that: The inductors L2, L3, L4, L5 and the capacitors C1, C2, C3, C4 are implemented in the form of lumped components, the inductors are spiral inductors, and the capacitors are MIM capacitors.

10. The Wilkinson power divider with a common ground capacitor structure according to claim 1, characterized in that: The isolation resistors R1 and R2 and the capacitors C1 and C2, C3 and C4 are integrated on the same circuit board, and the isolation resistors are thin film resistors.

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