CN219696694U - A miniaturized interdigitated microstrip type 90° mixer - Google Patents

Abstract

The utility model belongs to the field of radio frequency communication, and is specifically a miniaturized interdigital microstrip type 90° mixer. The first module and the second module of the mixer have the same structure, and both include a first high-impedance microstrip line, a plurality of first An open-circuit microstrip line and several second open-circuit microstrip lines; one end of each first open-circuit microstrip line is connected to the first high-impedance microstrip line, and the other end is open-circuited; one end of each second open-circuit microstrip line is connected to the floor connected, and the other end is open-circuited; several first open-circuit microstrip lines and several second open-circuit microstrip lines are staggered to form an interdigital structure, and there is an interdigital structure between the adjacent first open-circuit microstrip lines and the second open-circuit microstrip line There is a certain gap; the third module and the fourth module have the same structure and adopt a structure similar to the first module. The interdigitated structure microstrip type 90° mixer designed by this utility model has the advantages of miniaturization, low cost, stable performance, easy integration with other circuit modules, etc., and can better meet the needs of today's wireless communication systems.

Description

A miniaturized interdigitated microstrip type 90° mixer

Technical field

The utility model belongs to the field of radio frequency communication, and is specifically a miniaturized interdigital microstrip type 90° mixer.

Background technique

With the rapid development of wireless communication technology, higher and higher requirements have been placed on radio frequency devices, such as miniaturization, low cost, and excellent performance. As an important passive component in wireless communication systems, mixers have a wide range of applications. There are two main ways to design a mixer. One is to use lumped components to build a mixer. However, when lumped parameter components work at high frequencies, they will produce serious parasitic effects, which will worsen the performance of the mixer. Building mixers with components also increases processing and production costs; the other is to design a microstrip 90° mixer. Microstrip mixers have the advantages of low cost, stable performance, easy processing, and easy integration with other circuit modules. , but the traditional microstrip type 90° mixer is composed of four straight microstrip lines with an electrical length of 1/4 wavelength connected to each other. When working at low frequency, the structure size of the mixer is large, which is not conducive to the entire radio frequency communication. The miniaturization and integration of the system, therefore, the miniaturized, low-cost, and stable-performance microstrip 90° mixer has great research value and significance.

Contents of the invention

In order to solve the problems existing in the existing technology, the utility model designs an interdigitated microstrip type 90° mixer based on equivalent transmission line theory and microwave network theory. Its structural size is significantly reduced, and its performance meets the requirements. And it reduces the cost and can better meet the needs of today's wireless communication systems.

The utility model is realized through the following technical solutions: a miniaturized interdigital microstrip type 90° mixer, including a floor, a first module, a second module, a third module, a fourth module, an input port, a straight-through port, and a coupling port and isolation port; wherein, the input port is led out from between the first module and the third module, the through port is led out from between the first module and the fourth module, the coupling port is led out from between the second module and the fourth module, and the isolation port The port is led out between the second module and the third module;

The first module and the second module have the same structure, and both include a first high-impedance microstrip line, several first open-circuit microstrip lines, and several second open-circuit microstrip lines; one end of each first open-circuit microstrip line is connected to The first high-impedance microstrip line is connected and the other end is open-circuited; one end of each second open-circuit microstrip line is connected to the floor and the other end is open-circuited; several first open-circuit microstrip lines and several second open-circuit microstrip lines are staggered It forms an interdigital structure, and there is a gap between the adjacent first open-circuit microstrip line and the second open-circuit microstrip line;

The structures of the third module and the fourth module are the same, and both include a second high-impedance microstrip line, several third open-circuit microstrip lines, and several fourth open-circuit microstrip lines; one end of each third open-circuit microstrip line is connected to The second high-impedance microstrip line is connected and the other end is open-circuited; one end of each fourth open-circuit microstrip line is connected to the floor and the other end is open-circuited; several third open-circuit microstrip lines and several fourth open-circuit microstrip lines are staggered An interdigital structure is formed, and a gap is provided between the adjacent third open-circuit microstrip line and the fourth open-circuit microstrip line.

Preferably, two ends of the first high-impedance microstrip line in the first module are respectively connected to the input port and the through port; two ends of the first high-impedance line in the second module are respectively connected to the coupling port and the isolation port.

Preferably, the two ends of the second high-impedance microstrip line in the third module are respectively connected to the input port and the isolation port; the two ends of the second high-impedance microstrip line in the fourth module are respectively connected to the through port and the coupling port.

Preferably, the first high-impedance microstrip line is bent and folded into a polyline shape; and the second high-impedance microstrip line is bent and folded into a polygonal shape.

Preferably, the first module, the second module, the third module and the fourth module are all equivalent to microstrip lines with an electrical length of one-quarter wavelength.

Further preferably, the characteristic impedance of the equivalent microstrip line of the first module and the second module is smaller than the characteristic impedance of the equivalent microstrip line of the third module and the fourth module.

Preferably, in the first module and/or the second module, the first open-circuit microstrip line and the second open-circuit microstrip line have stronger inductive effects than capacitive effects; the adjacent first open-circuit microstrip line and the second open-circuit microstrip line have stronger The interdigital structure composed of open-circuit microstrip lines introduces capacitive effects.

Preferably, in the third module and/or the fourth module, the equivalent inductance effect of the third open-circuit microstrip line and the fourth open-circuit microstrip line is stronger than the capacitance effect; the adjacent third open-circuit microstrip line and the fourth open-circuit microstrip line are The interdigital structure composed of open-circuit microstrip lines introduces capacitive effects.

Compared with the existing technology, the utility model has the following advantages: the interdigitated microstrip type 90° mixer of the utility model has verified the correctness and feasibility of the circuit structure through electromagnetic simulation and experiments, and has the characteristics of miniaturization, low cost, With the advantages of stable performance and easy integration design with other circuit modules, it can better meet the needs of today's wireless communication systems.

Description of the drawings

Figure 1 is a schematic structural diagram of a miniaturized interdigitated microstrip type 90° mixer in an embodiment of the present utility model;

Figure 2 is a schematic diagram of the simulation results of the miniaturized mixer S11 (input matching) in the embodiment of the present invention;

Figure 3 is a schematic diagram of the transmission loss simulation results of the miniaturized mixer in the embodiment of the present invention;

Figure 4 is a schematic diagram of the phase difference simulation results of the miniaturized mixer in the embodiment of the present invention.

Detailed ways

The present utility model will be further described below in conjunction with the accompanying drawings and examples, but the implementation of the present utility model is not limited thereto.

Example

As shown in Figure 1, the miniaturized interdigital microstrip type 90° mixer of this embodiment includes a floor 9, a first module 1, a second module 2, a third module 3, a fourth module 4, and a first port 5 ( That is, the input port), the second port 6 (that is, the through port), the third port 7 (that is, the coupling port) and the fourth port 8 (that is, the isolation port); among them, the first port is from between the first module and the third module The second port is led out between the first module and the fourth module, the third port is led out between the second module and the fourth module, and the fourth port is led out between the second module and the third module.

In this embodiment, the first module, the second module, the third module and the fourth module are respectively arranged around the floor 9 so that the microstrip mixer is rectangular as a whole. The port and the fourth port are located at the four corners of the rectangle.

The first module and the second module have the same structure, and both include a first high-impedance microstrip line 13 , a plurality of first open-circuit microstrip lines 11 and a plurality of second open-circuit microstrip lines 12 . One end of each first open-circuit microstrip line is connected to the first high-impedance microstrip line, and the other end is open-circuited; one end of each second open-circuit microstrip line is connected to the floor 9, and the other end is open-circuited; several first open-circuit microstrip lines The lines and several second open-circuit microstrip lines are staggered to form an interdigital structure, and a certain gap is provided between adjacent first open-circuit microstrip lines and second open-circuit microstrip lines. The two ends of the first high-impedance microstrip line in the first module are connected to the first port and the second port respectively; the two ends of the first high-impedance line in the second module are connected to the third port and the fourth port respectively.

Similarly, the third module and the fourth module have the same structure, including a second high-impedance microstrip line 22 , a plurality of third open-circuit microstrip lines 31 and a plurality of fourth open-circuit microstrip lines 32 . One end of each third open-circuit microstrip line is connected to the second high-impedance microstrip line, and the other end is open-circuited; one end of each fourth open-circuit microstrip line is connected to the floor 9, and the other end is open-circuited; several third open-circuit microstrip lines The lines and several fourth open-circuit microstrip lines are staggered to form an interdigital structure, and a certain gap is provided between the adjacent third open-circuit microstrip lines and the fourth open-circuit microstrip lines. The two ends of the second high-impedance microstrip line in the third module are connected to the first port and the fourth port respectively; the two ends of the second high-impedance microstrip line in the fourth module are connected to the second port and the third port respectively. .

In addition, this embodiment is provided with a number of evenly arranged metallized vias 91 on the floor. The function of the via hole is to introduce the ground plane on the upper surface. Through the via hole, the metal surface on the upper surface and the metal ground on the back surface are connected to form a ground plane together.

In this embodiment, the first module and the second module can be equivalent to microstrip lines with a characteristic impedance of 35.3Ω and an electrical length of 1/4 wavelength. The functions between the structures of the first high-impedance microstrip line, the first open-circuit microstrip line, and the second open-circuit microstrip line of the first module and the second module are described as follows:

1. According to the theoretical knowledge of microwave circuits, the effects of microstrip circuits can be equivalent to the effects of concentrated component inductors and capacitors. The broadband of the first open-circuit microstrip line and the second open-circuit microstrip line is narrow, with a width of 0.2mm. , so the equivalent inductance effect of the first open-circuit microstrip line and the second open-circuit microstrip line is stronger than the capacitance effect, and the inductance effect accounts for the main part; the adjacent first open-circuit microstrip line and the second open-circuit microstrip line There is a certain gap between the lines, and the two open-circuit microstrip lines form an interdigital structure circuit, which helps to introduce the capacitance effect; the inductance effect produced by the first open-circuit microstrip line and the second open-circuit microstrip line itself and the two open circuits The capacitive effect produced by the interdigital structure circuit formed by the microstrip line structure is conducive to the realization of miniaturization characteristics.

2. Bend and fold the first high-impedance microstrip line and the second high-impedance microstrip line into a certain shape, such as a broken line shape, to fully utilize the internal space and further achieve miniaturization characteristics.

3. The line width of the first high-impedance microstrip line is very small, 0.2mm, and its equivalent inductance effect is strong. Moreover, the inductance effect produced by the first open-circuit microstrip line and the second open-circuit microstrip line itself and the two open-circuit microstrip lines The capacitance effect generated by the interdigital structure circuit formed by the strip structure causes a slow wave effect when the input signal passes through the first module, achieving miniaturization.

In this embodiment, the third module and the fourth module can be equivalent to microstrip lines with a characteristic impedance of 50Ω and an electrical length of 1/4 wavelength. In the same way, the same methods and theories can be used to analyze the structures in the third and fourth modules, and their effects and impacts are similar to those in the first and second modules.

Compared with the existing technology, the product structure of this utility model has the advantages of miniaturization, low cost, stable performance, and easy integration with other circuit modules. The detailed analysis is as follows:

1. The first open-circuit microstrip line and the second open-circuit microstrip line together form an interdigital structure circuit, producing a capacitive effect. The working principle is similar to a parallel plate capacitor; the first open-circuit microstrip line and the second open-circuit microstrip line are The smaller the spacing, the stronger the capacitive effect it produces, which is more conducive to miniaturization. At the same time, the capacitive effect formed between the first open-circuit microstrip line and the second open-circuit microstrip line can replace the lumped capacitance element, further reducing the cost of the mixer. In the same way, the interdigital structure circuit formed by the third open-circuit microstrip line and the fourth open-circuit microstrip line has the same effect.

2. Bend and fold the first high-impedance microstrip line and the second high-impedance microstrip line into a certain shape, such as a broken line shape, to make full use of the internal space and facilitate miniaturization.

3. The line width of the first high-impedance microstrip line in the first module and the second module is very small, and the equivalent inductance effect produced by it is strong. At the same time, there is a gap between the first open-circuit microstrip line and the second open-circuit microstrip line. Produce a strong capacitive effect. Due to the inductance and capacitance effects generated by the first module and the second module, a slow wave effect will be generated when the input signal passes through the module, which is conducive to miniaturization. The principle analysis of its slow wave effect is as follows:

It can be seen from the following three formulas that when the equivalent inductance and capacitance effects on the transmission line are increased at the same time and in equal proportions, the characteristic impedance Z ₀ of the transmission line remains unchanged, but the phase velocity Vp of the signal on the transmission line becomes smaller, so in Under the same operating frequency, the wave travel λ of the transmission line becomes smaller, and the corresponding physical size becomes smaller as the wavelength becomes smaller, thereby achieving the purpose of miniaturization.

Therefore, under the same operating frequency, the utility model introduces the slow wave effect into the structure to make the physical size of the mixer smaller, thereby achieving the purpose of miniaturization.

The equivalent inductance effect of the first high-impedance microstrip line in the first module and the second module and the capacitive effect generated by the interdigital structure circuit formed between the first open-circuit microstrip line and the second open-circuit microstrip line are based on the principle of slow wave effect. , thereby achieving the purpose of miniaturization. In the same way, the working principles of the third module and the fourth module are similar to those of the first module and the second module.

4. Based on the above theoretical analysis, electromagnetic modeling simulation and experimental demonstration were conducted on the miniaturized interdigitated microstrip 90° mixer. From the simulation results in Figure 2, Figure 3, and Figure 4, it can be seen that the The structure has excellent performance, and the size and area of the structure in Figure 1 is reduced by approximately 77% compared to a traditional mixer.

The above are only the preferred/preferred embodiments of the utility model patent invention. However, the protection scope of the invention patent is not limited thereto. Any other changes, modifications, modifications, etc. may be made without departing from the spirit and principle of the utility model patent. Substitution, combination, and simplification should all be equivalent replacement methods, and are all included in the protection scope of the present utility model.

Claims (10)

1. A miniaturized interdigital microstrip type 90-degree mixer comprises a floor, a first module, a second module, a third module, a fourth module, an input port, a through port, a coupling port and an isolation port; the input port is led out from between the first module and the third module, the straight-through port is led out from between the first module and the fourth module, the coupling port is led out from between the second module and the fourth module, and the isolation port is led out from between the second module and the third module; the method is characterized in that:

the first module and the second module have the same structure and comprise a first high-impedance microstrip line, a plurality of first open-circuit microstrip lines and a plurality of second open-circuit microstrip lines; one end of each first open-circuit microstrip line is connected with the first high-impedance microstrip line, and the other end of each first open-circuit microstrip line is open-circuited; one end of each second open-circuit microstrip line is connected with the floor, and the other end of each second open-circuit microstrip line is open-circuited; the first open-circuit microstrip lines and the second open-circuit microstrip lines are arranged in a staggered mode to form an interdigital structure, and gaps are formed between the adjacent first open-circuit microstrip lines and the adjacent second open-circuit microstrip lines;

the third module and the fourth module have the same structure and comprise a second high-impedance microstrip line, a plurality of third open-circuit microstrip lines and a plurality of fourth open-circuit microstrip lines; one end of each third open-circuit microstrip line is connected with the second high-impedance microstrip line, and the other end of each third open-circuit microstrip line is open-circuited; one end of each fourth-path microstrip line is connected with the floor, and the other end is opened; the third open-circuit microstrip lines and the fourth open-circuit microstrip lines are arranged in a staggered mode to form an interdigital structure, and gaps are arranged between the adjacent third open-circuit microstrip lines and fourth open-circuit microstrip lines.

2. The microstrip type 90 ° hybrid according to claim 1, wherein both ends of the first high impedance microstrip line in the first module are connected to the input port and the through port, respectively; two ends of a first high-impedance line in the second module are respectively connected with the coupling port and the isolation port.

3. The microstrip type 90 ° hybrid according to claim 1, wherein both ends of the second high impedance microstrip line in the third module are connected to the input port and the isolation port, respectively; and two ends of the second high-impedance microstrip line in the fourth module are respectively connected with the through port and the coupling port.

4. The microstrip type 90 ° hybrid according to claim 1, wherein the first high impedance microstrip line is folded in a meander line shape.

5. The microstrip type 90 ° hybrid according to claim 1, wherein the second high impedance microstrip line is folded in a meander line shape.

6. The microstrip type 90 ° hybrid according to claim 1, wherein the first module, the second module, the third module and the fourth module are all equivalent to microstrip lines having an electrical length of one quarter wavelength.

7. The microstrip 90 ° hybrid of claim 6, wherein the characteristic impedance of the microstrip line equivalent to the first and second modules is less than the characteristic impedance of the microstrip line equivalent to the third and fourth modules.

8. The microstrip type 90 ° hybrid according to claim 1, wherein a plurality of uniformly arranged metallized vias are provided on the floor.

9. The microstrip type 90 ° hybrid according to claim 1, wherein in the first module and/or the second module, the first open-circuit microstrip line and the second open-circuit microstrip line have a stronger self-equivalent inductance effect than capacitance effect; the interdigital structure formed by the adjacent first open-circuit microstrip line and second open-circuit microstrip line introduces a capacitance effect.

10. The microstrip type 90 ° hybrid according to claim 1, wherein in the third module and/or the fourth module, the third open-circuit microstrip line and the fourth open-circuit microstrip line have a stronger self-equivalent inductance effect than capacitance effect; the interdigital structure formed by the adjacent third open-circuit microstrip line and fourth open-circuit microstrip line introduces a capacitance effect.