Miniaturized metal plate strip line quadripole

Abstract

The application discloses a miniaturized sheet metal strip line quadruplexer, and relates to the technical field of communication equipment. In the quadruplexer, an impedance matching network and four-way channel filters are arranged. Two-way channel filters are arranged on the two sides of the impedance matching network, and the other two-way channel filters are arranged in parallel with the previous two-way channel filters on the back side of the impedance matching network. The impedance matching network and the four-way channel filters are connected with five port connectors, so that a multiplexer structure with one input and four outputs is realized. The impedance matching network comprises a common strip line resonator, and each of the four-way channel filters comprises four strip line resonators connected in parallel. The common strip line resonator is coupled with the first strip line resonator of each channel filter, so that impedance matching between the impedance matching network and each channel filter is realized. Compared with the prior art, the miniaturized sheet metal strip line quadruplexer has the advantages of miniaturization, easy integration, high performance and high reliability.

Description

TECHNICAL FIELD

[0001] The application relates to the technical field of communication equipment, in particular to a miniaturized sheet metal strip line quadrupler. BACKGROUND

[0002] A multiplexer is composed of a group of non-overlapping filters, that is, composed of multiple channel filters, and the channel filters are not loaded with each other and have high isolation between each other. The multiplexer is mainly composed of an impedance matching network (common tap structure) and a plurality of (N>2) channel filters, and when multiple frequency bands work at the same time, the high isolation between the channel frequency bands is ensured to avoid signal interference, thereby ensuring the stability of communication. The quadrupler, as the name implies, is to combine four channel filters and share a node (also known as a common tap structure or impedance matching network). The complexity of the quadrupler is much higher than that of the duplexer and the triplexer, because the four channel filters must be designed together and meet strict cross-isolation specifications.

[0003] The quadrupler commonly used in the industry and widely applied mainly includes a coaxial cavity quadrupler, a metal waveguide quadrupler, a microstrip quadrupler and a dielectric waveguide quadrupler. The coaxial cavity quadrupler and the metal waveguide quadrupler have the advantages of small loss, large power capacity and high reliability, but the product size and weight are large, and the miniaturization and light weight use scenarios are limited; the microstrip quadrupler has the advantages of planarization and easy integration, but its own loss is very large and cannot be applied to the scene with high loss requirement such as radio frequency front end; the dielectric waveguide quadrupler has a large porcelain body, and a large-tonnage press is required in the dry pressing process, and the porcelain body is easy to warp and crack after the body is sintered, and the long-term reliability is general.

[0004] Therefore, in order to overcome the shortcomings of the prior art, it is urgent to need a new structure of multiplexer to realize the comprehensive advantages of miniaturization, easy integration, high performance and high reliability. SUMMARY

[0005] The purpose of the application is to provide a miniaturized sheet metal strip line quadrupler, which has the comprehensive advantages of novel structure, miniaturization, easy integration, high performance and high reliability.

[0006] To achieve the above purpose, the application provides the following solutions:

[0007] In a first aspect, the application provides a miniaturized strip-line four-way filter, comprising a bottom plate, a resonator frame and a cover plate; the bottom plate and the cover plate are respectively mounted on the bottom surface and the top surface of the resonator frame through positioning pins on the resonator frame and are fixed by soldering tin sealing; the resonator frame is fixed with a first channel filter, a second channel filter, a third channel filter, a fourth channel filter and an impedance matching network, the working frequency bands of the first channel filter, the second channel filter, the third channel filter and the fourth channel filter are arranged from low to high, the first channel filter and the second channel filter are arranged side by side on the back side of the impedance matching network, and the third channel filter and the fourth channel filter are arranged on the two sides of the impedance matching network; five port connectors are arranged on the resonator frame, the inner cores of the five port connectors pass through the bottom plate and are connected with the impedance matching network, the first channel filter, the second channel filter, the third channel filter and the fourth channel filter respectively.

[0008] The impedance matching network comprises a common strip-line resonator, the first channel filter, the second channel filter, the third channel filter and the fourth channel filter each comprise four strip-line resonators connected side by side, the bottom of each strip-line resonator is fixedly soldered on the bottom plate, a plurality of tuning screws are arranged on the cover plate at positions corresponding to the strip-line resonators, and the tuning screws are used for adjusting the resonant frequency of the corresponding strip-line resonator; the common strip-line resonator is coupled with the first strip-line resonator of the first channel filter, the first strip-line resonator of the second channel filter, the first strip-line resonator of the third channel filter and the first strip-line resonator of the fourth channel filter respectively, so as to realize impedance matching between the impedance matching network and the first channel filter, the second channel filter, the third channel filter and the fourth channel filter.

[0009] Optionally, frequency-variable coupling between the second strip-line resonator of the first channel filter and the third strip-line resonator of the first channel filter produces a transmission zero point outside the high end of the passband of the first channel filter.

[0010] Frequency-variable coupling between the second strip-line resonator of the second channel filter and the third strip-line resonator of the second channel filter produces a transmission zero point outside the high end of the passband of the second channel filter.

[0011] Frequency-variable coupling between the second strip-line resonator of the third channel filter and the third strip-line resonator of the third channel filter produces a transmission zero point outside the low end of the passband of the third channel filter.

[0012] Frequency-variable coupling between the second strip-line resonator of the fourth channel filter and the third strip-line resonator of the fourth channel filter produces a transmission zero point outside the low end of the passband of the fourth channel filter.

[0013] Optionally, each strip-line resonator of the first channel filter and each strip-line resonator of the third channel filter are arranged in parallel, and each strip-line resonator of the first channel filter is staggered with a corresponding strip-line resonator of the third channel filter by a distance of half the width of a strip-line resonator.

[0014] Each strip-line resonator of the second channel filter and each strip-line resonator of the fourth channel filter are arranged in parallel, and each strip-line resonator of the second channel filter is staggered with a corresponding strip-line resonator of the fourth channel filter by a distance of half the width of a strip-line resonator.

[0015] The third channel filter is arranged at the left side of the common strip-line resonator, and the right side stub of the first strip-line resonator of the first channel filter is arranged opposite to the left side stub of the common strip-line resonator; the fourth channel filter is arranged at the right side of the common strip-line resonator, and the left side stub of the first strip-line resonator of the second channel filter is arranged opposite to the right side stub of the common strip-line resonator.

[0016] Optionally, each strip-line resonator and the common strip-line resonator are strip-line stepped-impedance resonators; the electric field of the strip-line stepped-impedance resonator is concentrated in the upper half of the strip-line stepped-impedance resonator, and the magnetic field of the strip-line stepped-impedance resonator is concentrated in the lower half of the strip-line stepped-impedance resonator.

[0017] Optionally, the right side stub of the first strip-line resonator of the first channel filter is electrically coupled with the left side stub of the common strip-line resonator, and the left side stub of the first strip-line resonator of the second channel filter is electrically coupled with the right side stub of the common strip-line resonator; the first strip-line resonator of the third channel filter is magnetically coupled with the common strip-line resonator, and the first strip-line resonator of the fourth channel filter is magnetically coupled with the common strip-line resonator.

[0018] Optionally, the right side stub of the first strip-line resonator of the first channel filter is electrically coupled with the left side stub of the common strip-line resonator, and the left side stub of the first strip-line resonator of the second channel filter is electrically coupled with the right side stub of the common strip-line resonator; the right side stub of the first strip-line resonator of the third channel filter is electrically coupled with the left side stub of the common strip-line resonator, and the first strip-line resonator of the fourth channel filter is magnetically coupled with the common strip-line resonator.

[0019] Optionally, the right branch of the first stripline resonator of the first channel filter is electrically coupled to the left branch of the common stripline resonator, the left branch of the first stripline resonator of the second channel filter is electrically coupled to the right branch of the common stripline resonator; the right branch of the first stripline resonator of the third channel filter is electrically coupled to the left branch of the common stripline resonator, and the left branch of the first stripline resonator of the fourth channel filter is electrically coupled to the right branch of the common stripline resonator.

[0020] Optionally, the first stripline resonator of the first channel filter is magnetically coupled to the common stripline resonator, the first stripline resonator of the second channel filter is magnetically coupled to the common stripline resonator, the first stripline resonator of the third channel filter is magnetically coupled to the common stripline resonator, and the first stripline resonator of the fourth channel filter is magnetically coupled to the common stripline resonator.

[0021] Optionally, the magnetic coupling is that the lower half of the two stripline resonators is connected by a reinforcing rib; the distance between the reinforcing rib and the bottom plate is proportional to the magnetic coupling strength between the two stripline resonators.

[0022] Optionally, the electrical coupling is that the branches of the upper half of the two stripline resonators are isolated without obstacles; the distance between the branches of the upper half of the two stripline resonators is inversely proportional to the electrical coupling degree between the two stripline resonators.

[0023] According to the specific embodiments provided in the application, the following technical effects are disclosed in the application:

[0024] The application provides a miniaturized sheet metal strip line quadruplexer, in which a bottom plate and a cover plate are fixed on the bottom surface and the top surface of a resonator frame body by means of soldering tin sealing, an impedance matching network and a four-way channel filter are fixed in the resonator frame body, the working frequency bands of the four-way channel filter are arranged from low to high, the bottom ends of the four-way channel filter are fixed and installed on the bottom plate, the first channel filter and the second channel filter are arranged side by side on the rear side of the impedance matching network, and the third channel filter and the fourth channel filter are arranged on the two sides of the impedance matching network; the impedance matching network and the four-way channel filter are connected with five port connectors respectively, so that a one-input four-output structure is realized; the impedance matching network comprises one common strip line resonator, the four-way channel filter comprises four strip line resonators connected side by side, and a corresponding number of tuning screws are arranged, which can be used for adjusting the resonant frequency of the corresponding strip line resonator; the common strip line resonator is coupled with the first strip line resonator of each channel filter, so that the impedance matching between the impedance matching network and each channel filter is realized. The miniaturized sheet metal strip line quadruplexer has a unique and compact structure, can flexibly introduce a frequency change coupling structure between the resonators of the four-way channel filter, meets the demand of product electrical performance design, and is easy to realize multiple transmission zeros, so that the effects of high out-of-band suppression and high channel isolation are achieved. Compared with the quadruplexer products on the market, the miniaturized sheet metal strip line quadruplexer has the advantages of miniaturization, high performance, easy integration and high reliability. In addition, due to the compact structure, the production and assembly are simple, and the debugging is easy, so the miniaturized sheet metal strip line quadruplexer has wide application potential in the wireless communication field with high requirements for electrical performance and miniaturization. BRIEF DESCRIPTION OF DRAWINGS

[0025] In order to more clearly illustrate the technical solutions in the embodiments of the application or the prior art, the following will briefly introduce the drawings needed in the embodiments. Obviously, the drawings in the following description only constitute some embodiments of the application, and for those skilled in the art, other drawings can also be obtained from these drawings without creative labor.

[0026] Figure 1 An external structure schematic diagram of a miniaturized sheet metal strip line quadruplexer provided by an embodiment of the application.

[0027] Figure 2 An exploded schematic diagram of the structure of a miniaturized sheet metal strip line quadruplexer provided by an embodiment of the application.

[0028] Figure 3 An internal structure schematic diagram of a miniaturized sheet metal strip line quadruplexer provided by an embodiment of the application.

[0029] Figure 4A local enlarged schematic view of an impedance matching network of a small-sized metal plate strip-line quadripole is provided for an embodiment of the present application.

[0030] Figure 5 A frequency characteristic response curve schematic view of a small-sized metal plate strip-line quadripole is provided for an embodiment of the present application.

[0031] Figure 6 An electric field distribution schematic view of a strip-line stepped impedance resonator of a small-sized metal plate strip-line quadripole is provided for another embodiment of the present application.

[0032] Figure 7 A group delay curve schematic view of an impedance matching network of a small-sized metal plate strip-line quadripole is provided for an embodiment of the present application.

[0033] Figure 8 An external structure schematic view of a small-sized metal plate strip-line quadripole is provided for another embodiment of the present application.

[0034] Figure 9 An internal structure schematic view of a small-sized metal plate strip-line quadripole is provided for another embodiment of the present application.

[0035] Figure 10 An internal structure schematic view of a small-sized metal plate strip-line quadripole is provided for another embodiment of the present application.

[0036] Figure 11 An internal structure schematic view of a small-sized metal plate strip-line quadripole is provided for another embodiment of the present application.

[0037] Figure 12 An internal structure schematic view of a small-sized metal plate strip-line quadripole is provided for another embodiment of the present application.

[0038] Reference signs:

[0039] 100: common band-line resonator; 201: first band-line resonator of the first channel filter; 202: second band-line resonator of the first channel filter; 203: third band-line resonator of the first channel filter; 204: fourth band-line resonator of the first channel filter; 301: first band-line resonator of the second channel filter; 302: second band-line resonator of the second channel filter; 303: third band-line resonator of the second channel filter; 304: fourth band-line resonator of the second channel filter; 401: first band-line resonator of the third channel filter; 402: second band-line resonator of the third channel filter; 403: third band-line resonator of the third channel filter; 404: fourth band-line resonator of the third channel filter; 501: first band-line resonator of the fourth channel filter; 502: second band-line resonator of the fourth channel filter; 503: third band-line resonator of the fourth channel filter; 504: fourth band-line resonator of the fourth channel filter; Port 1: input port; Port 2-Port 5: output ports. DETAILED DESCRIPTION

[0040] The technical solutions in the embodiments of the present application will be clearly and completely described below with reference to the drawings in the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, rather than all the embodiments of the present application. Based on the embodiments in the present application, all other embodiments obtained by those of ordinary skill in the art without creative work fall within the scope of protection of the present application.

[0041] With the rapid development of wireless communication technology, the demand for efficient spectrum and high-speed data transmission of communication systems is increasingly urgent, leading to the continuous emergence of multi-frequency integrated miniaturized communication devices. In order to maximize the utilization rate of spectrum resources and reduce interference, multiplex communication technology is essential. So-called multiplex communication is to allow communication devices to transmit and receive signals on two or more frequency bands at the same time. In this process, the multiplexer plays a key role, which can combine multiple signals into a single channel and provide an unobstructed path for data signal transmission. Duplexer, triplexer and quadruplexer all belong to the category of multiplexer, which usually has one input port and multiple output ports.

[0042] The multiplexer is composed of a set of non-overlapping filters, that is, composed of multiple channel filters which do not interfere with each other and have high isolation. The multiplexer is mainly composed of an impedance matching network (common tap structure) and a plurality of (N≥2) channel filters to ensure that when multiple frequency bands work at the same time, each channel maintains high isolation, avoids signal interference, and thus ensures the stability of communication. The quadruplexer combines four channel filters and shares a node (also known as a common tap structure or matching network). Compared with the diplexer and triplexer, the design of the quadruplexer is more complex because the four channel filters must be designed together and meet strict cross-isolation specifications.

[0043] In the industry, common types of quadruplexers include coaxial cavity quadruplexers, metal waveguide quadruplexers, microstrip quadruplexers, and dielectric waveguide quadruplexers. Metal cavity quadruplexers are known for their low loss, high power capacity, and high reliability, but their product size and weight are large, limiting their application in miniaturization and lightweight scenarios; microstrip quadruplexers have the advantages of planarization and easy integration, but their own loss is large, making them unsuitable for RF front-end scenarios with high loss requirements; dielectric waveguide quadruplexers have a large ceramic body size, requiring a large-tonnage press during dry pressing, and the sintered body is prone to warping, so the ceramic body is prone to cracking, and the long-term reliability is generally poor.

[0044] Therefore, the present application innovatively develops a compact miniaturized sheet metal strip line quadruplexer, which has high performance and reliability second only to metal coaxial cavity quadruplexers, and also has the advantages of miniaturization and easy integration of dielectric waveguide quadruplexers.

[0045] To make the above-mentioned purposes, features and advantages of the present application more obvious and easy to understand, the present application will be further described in detail below in combination with the drawings and specific embodiments.

[0046] In an exemplary embodiment, as shown in Figure 1 A compact sheet metal strip line quadruplexer is provided, comprising a bottom plate, a resonator frame, and a cover plate; the bottom plate and the cover plate are respectively mounted on the bottom surface and the top surface of the resonator frame through the positioning pins on the resonator frame and are fixed by soldering tin sealing; as an embodiment, the cover plate and the bottom plate are pre-assembled with the frame through the positioning pins, and then the cover plate and the bottom plate are fixed on the upper surface and the lower surface of the frame by tin sealing welding. Further, as shown in Figure 2The structure explosion diagram shows that the first channel filter, the second channel filter, the third channel filter, the fourth channel filter and the impedance matching network are fixed in the resonator frame, the working frequency bands of the first channel filter, the second channel filter, the third channel filter and the fourth channel filter are arranged from low to high, the first channel filter and the second channel filter are arranged side by side at the back side of the impedance matching network, and the third channel filter and the fourth channel filter are arranged on the two sides of the impedance matching network respectively; each channel filter can be processed by wire cutting or stamped into shape, each channel filter is installed on the corresponding position of the bottom plate through a tool, and is fixed by laser welding. Five port connectors are arranged on the resonator frame, the inner cores of the five port connectors pass through the bottom plate and are connected with the impedance matching network, the first channel filter, the second channel filter, the third channel filter and the fourth channel filter respectively, a plurality of tuning screws are arranged on the cover plate at the positions corresponding to the strip-line resonators, and the tuning screws are used for adjusting the resonant frequency of the corresponding strip-line resonator. The small-sized sheet metal strip-line quadrupler has few accessories, simple assembly process and convenient debugging.

[0047] As an embodiment, the cover plate, the frame and the bottom plate and the like structural members of the small-sized sheet metal strip-line quadrupler can be made of copper material, aluminum material, iron material and stainless steel and the like metal materials as base materials and then electroplated with silver; the cover plate, the resonator frame and the bottom plate and the like structural members can also be made of plastic materials such as PEEK, POM, PPO and PET and the like medium materials and then electroplated with silver, so that the weight of the product can be reduced by more than 30%, and the light weight is realized.

[0048] The impedance matching network includes a common strip-line resonator 100, the first channel filter, the second channel filter, the third channel filter and the fourth channel filter each include four strip-line resonators connected side by side, each channel filter is arranged in a straight line, and the resonators are connected through the introduction of a frequency-variable coupling structure to generate a transmission zero point, so as to improve the out-of-band suppression characteristics of the channel filter and enhance the isolation of each channel filter device. Figure 3 As shown, 201-204 are four resonators of the first channel filter, 301-304 are four resonators of the second channel filter, 401-404 are four resonators of the third channel filter, and 501-504 are four resonators of the fourth channel filter, the bottom of each strip-line resonator is fixed and welded on the bottom plate, and the bottom plate is provided with mounting and welding holes; the small-sized sheet metal strip-line quadrupler is a multiple filter with one input and four outputs, the input port Port1 is arranged on the strip-line resonator 100, and the four output ports Port2, Port3, Port4 and Port5 are arranged on the strip-line resonators 204, 304, 404 and 504 respectively; the input and output ports are matched with 50 ohms. As shown in Figure 4As shown in the partial enlarged view, the common line resonator 100 is coupled with the first line resonator 201 of the first channel filter, the first line resonator 301 of the second channel filter, the first line resonator 401 of the third channel filter, and the first line resonator 501 of the fourth channel filter respectively, so as to realize the impedance matching network between the impedance matching network and the first channel filter, the second channel filter, the third channel filter, and the fourth channel filter.

[0049] As an optional embodiment, the frequency-variable coupling between the second line resonator 202 of the first channel filter and the third line resonator 203 of the first channel filter generates a transmission zero point outside the high end of the passband of the first channel filter. The frequency-variable coupling between the second line resonator 302 of the second channel filter and the third line resonator 303 of the second channel filter generates a transmission zero point outside the high end of the passband of the second channel filter. The frequency-variable coupling between the second line resonator 402 of the third channel filter and the third line resonator 403 of the third channel filter generates a transmission zero point outside the low end of the passband of the third channel filter. The frequency-variable coupling between the second line resonator 502 of the fourth channel filter and the third line resonator 503 of the fourth channel filter generates a transmission zero point outside the low end of the passband of the fourth channel filter. The frequency characteristic response curve of the miniaturized metal line four-way filter is shown in Figure 5 As shown, S11 represents the reflection coefficient at port Port1; S21 represents the transmission coefficient from port Port2 to port Port1; S31 represents the transmission coefficient from port Port3 to port Port1; S41 represents the transmission coefficient from port Port4 to port Port1; and S51 represents the transmission coefficient from port Port5 to port Port1.

[0050] As an exemplary embodiment, as shown in Figure 3 As shown, the line resonators of the first channel filter and the line resonators of the third channel filter are arranged in parallel, and the line resonators of the first channel filter are staggered by a distance of half the width of a line resonator from the corresponding line resonators of the third channel filter.

[0051] The line resonators of the second channel filter and the line resonators of the fourth channel filter are arranged in parallel, and the line resonators of the second channel filter are staggered by a distance of half the width of a line resonator from the corresponding line resonators of the fourth channel filter.

[0052] The third channel filter is arranged at the left side of the common strip-line resonator 100, and the right side stub of the first strip-line resonator 201 of the first channel filter is arranged opposite to the left side stub of the common strip-line resonator 100; the fourth channel filter is arranged at the right side of the common strip-line resonator 100, and the left side stub of the first strip-line resonator 301 of the second channel filter is arranged opposite to the right side stub of the common strip-line resonator 100.

[0053] As an exemplary embodiment, the strip-line resonators in each channel filter and the common strip-line resonator 100 are all strip-line stepped-impedance resonators; the electric field of the strip-line stepped-impedance resonator is concentratedly distributed in the upper half of the strip-line stepped-impedance resonator, and the magnetic field of the strip-line stepped-impedance resonator is concentratedly distributed in the lower half of the strip-line stepped-impedance resonator. As shown in the electric field distribution diagrams of two SIR strip-line resonators in FIG. 2, the electric field distribution of the two resonators is similar, and the electric field is concentratedly distributed in the upper half of the strip-line. Figure 6

[0054] In the product design, the coupling polarity between the common strip-line resonator 100 and the first strip-line resonators 201, 301, 401 and 501 of each channel filter can be flexibly arranged according to the needs, and the common strip-line resonator 100 and the first strip-line resonator of each channel filter can be magnetically coupled or electrically coupled.

[0055] In an embodiment of the present application, the right side stub of the first strip-line resonator 201 of the first channel filter is electrically coupled with the left side stub of the common strip-line resonator 100, and the left side stub of the first strip-line resonator 301 of the second channel filter is electrically coupled with the right side stub of the common strip-line resonator 100; the electric coupling is that the stubs in the upper half of the two strip-line resonators are not isolated; the distance between the stubs in the upper half of the two strip-line resonators is inversely proportional to the electric coupling degree between the two strip-line resonators.

[0056] The first strip-line resonator 401 of the third channel filter is magnetically coupled with the common strip-line resonator 100, and the first strip-line resonator 501 of the fourth channel filter is magnetically coupled with the common strip-line resonator 100. The magnetic coupling is that the lower half of the two strip-line resonators are connected through the reinforcing ribs; the distance between the reinforcing ribs and the bottom plate is proportional to the magnetic coupling strength between the two strip-line resonators.

[0057] The impedance matching network of the miniaturized strip-line four-way filter is designed ingeniously and flexibly, and can conveniently realize the impedance matching and coupling control between the strip-line resonator 100 and the four-way channel filter. The corresponding group delay curve is shown in FIG. 4. Figure 7 Figure 7 ​​The four protrusions in the figure represent the strength of the coupling between the common stripline resonator 100 and the four channel filters. Each protrusion corresponds to a time delay peak at the center frequency of each channel filter. The stronger the coupling, the lower the time delay peak, and GD(1, 1) represents the group delay at the input port Port1. The weaker the coupling, the weaker the time delay peak. By adjusting the distance between the reinforcing ribs and the bottom plate, as well as the distance between the branches, the strength of the corresponding coupling structure can be controlled, i.e., the height of the corresponding time delay peak can be controlled.

[0058] In another exemplary embodiment of the present application, the external structure of the miniaturized sheet metal stripline quadruplexer can be expanded according to the installation application scenario of the product. The input and output port connectors can adopt a probe-to-socket connection mode (in which the input and output port probes are on the bottom plate), which is easy to integrate with other circuits for installation, or can adopt a traditional coaxial connector (the coaxial connector is mounted on the resonator frame) for external connection, as shown in Figure 8 .

[0059] In addition, in addition to the above coupling mode between the four-channel channel filter and the impedance matching network, other coupling modes can also be used. In another exemplary embodiment of the present application, as shown in Figure 9 , the right branch of the first stripline resonator 201 of the first channel filter is electrically coupled to the left branch of the common stripline resonator 100, and the left branch of the first stripline resonator 301 of the second channel filter is electrically coupled to the right branch of the common stripline resonator 100. The right branch of the first stripline resonator 401 of the third channel filter is electrically coupled to the left branch of the common stripline resonator 100, and the left branch of the first stripline resonator 501 of the fourth channel filter is magnetically coupled to the common stripline resonator 100.

[0060] In another exemplary embodiment of the present application, as shown in Figure 10 , the right branch of the first stripline resonator 201 of the first channel filter is electrically coupled to the left branch of the common stripline resonator 100, and the left branch of the first stripline resonator 301 of the second channel filter is electrically coupled to the right branch of the common stripline resonator 100. The right branch of the first stripline resonator 401 of the third channel filter is electrically coupled to the left branch of the common stripline resonator 100, and the left branch of the first stripline resonator 501 of the fourth channel filter is electrically coupled to the right branch of the common stripline resonator 100.

[0061] In another exemplary embodiment of the present application, as shown in Figure 11As shown, the right side stub of the first stripline resonator 201 of the first channel filter is electrically coupled with the left side stub of the common stripline resonator 100, the first stripline resonator 301 of the second channel filter is magnetically coupled with the common stripline resonator 100, the first stripline resonator 401 of the third channel filter is magnetically coupled with the common stripline resonator 100, and the first stripline resonator 501 of the fourth channel filter is magnetically coupled with the common stripline resonator 100.

[0062] In another exemplary embodiment of the present application, as shown in Figure 12 As shown, the first stripline resonator 201 of the first channel filter is magnetically coupled with the common stripline resonator 100, the first stripline resonator 301 of the second channel filter is magnetically coupled with the common stripline resonator 100, the first stripline resonator 401 of the third channel filter is magnetically coupled with the common stripline resonator 100, and the first stripline resonator 501 of the fourth channel filter is magnetically coupled with the common stripline resonator 100.

[0063] The above-mentioned miniaturized metal strip line four-way filter proposed in the present application mainly comprises an impedance matching network with novel structure and channel filters arranged by four stripline resonators. The miniaturized metal strip line four-way filter has novel and compact structure, small product size, straight line arrangement of each channel filter, convenient introduction of frequency-variable coupling structure into the resonators of each channel filter to generate transmission zero point, improved out-of-band suppression degree of the channel filter and isolation degree between each channel filter. The coupling between the common stripline resonator and the first resonator of each channel filter can be electrical coupling or magnetic coupling, and the coupling has novel and compact structure, flexible and rich coupling implementation, and flexible control of coupling polarity and strength. In addition, the material cost of the four-way filter is low, the power capacity is comparable to that of a small metal coaxial cavity four-way filter, the single-cavity Q value is high, the insertion loss is small (greater than that of a dielectric waveguide resonator and slightly smaller than that of a metal coaxial resonator), the harmonic suppression characteristic is good, the material structure of the miniaturized metal strip line four-way filter is less, the assembly is simple, the resonator frame, cover plate and bottom plate are fixed together by tin soldering, the resonator metal sheet and the bottom plate are fixed by laser welding, the product has high reliability and good intermodulation characteristic, and has wide application potential in the wireless communication field with extremely high requirements for electrical performance and miniaturization.

[0064] The technical features of the above embodiments can be combined in any manner. To make the description concise, not all possible combinations of the technical features in the above embodiments are described, but as long as the combinations of the technical features do not contradict, they should be considered as within the scope of the present disclosure.

[0065] The principles and implementation manners of the present application are described herein by using specific examples, and the above examples are only used to help understand the method of the present application and its core idea; meanwhile, for those skilled in the art, according to the idea of the present application, the specific implementation manners and application ranges will have changes. In conclusion, the content of the specification should not be understood as a limitation of the present application.

Claims

1. A miniaturized metal strip line quadripole, characterized in that, The application relates to a filter, which comprises a bottom plate, a resonator frame and a cover plate; the bottom plate and the cover plate are respectively arranged on the bottom surface and the top surface of the resonator frame through positioning pins on the resonator frame and are fixed through soldering tin sealing; a first channel filter, a second channel filter, a third channel filter, a fourth channel filter and an impedance matching network are fixed in the resonator frame; the working frequency bands of the first channel filter, the second channel filter, the third channel filter and the fourth channel filter are arranged from low to high; the first channel filter and the second channel filter are arranged side by side on the back side of the impedance matching network; the third channel filter and the fourth channel filter are arranged on the two sides of the impedance matching network; five port connectors are arranged on the resonator frame, and the inner cores of the five port connectors pass through the bottom plate and are connected with the impedance matching network, the first channel filter, the second channel filter, the third channel filter and the fourth channel filter respectively. The impedance matching network comprises a common strip-line resonator; the first channel filter, the second channel filter, the third channel filter and the fourth channel filter each comprise four strip-line resonators which are connected side by side; the bottom of each strip-line resonator is fixed and welded on the bottom plate; a plurality of tuning screws are arranged on the cover plate at positions corresponding to the strip-line resonators; the tuning screws are used for adjusting the resonant frequency of the corresponding strip-line resonator; the common strip-line resonator is coupled with the first strip-line resonator of the first channel filter, the first strip-line resonator of the second channel filter, the first strip-line resonator of the third channel filter and the first strip-line resonator of the fourth channel filter respectively, so as to realize impedance matching between the impedance matching network and the first channel filter, the second channel filter, the third channel filter and the fourth channel filter. Frequency-variable coupling between the second strip-line resonator of the first channel filter and the third strip-line resonator of the first channel filter generates a transmission zero point outside the high end of the passband of the first channel filter; 2. The miniaturized planar quadripole according to claim 1, characterized in that, Frequency-variable coupling between the second strip-line resonator of the second channel filter and the third strip-line resonator of the second channel filter generates a transmission zero point outside the high end of the passband of the second channel filter; Frequency-variable coupling between the second strip-line resonator of the third channel filter and the third strip-line resonator of the third channel filter generates a transmission zero point outside the low end of the passband of the third channel filter; Frequency-variable coupling between the second strip-line resonator of the fourth channel filter and the third strip-line resonator of the fourth channel filter generates a transmission zero point outside the low end of the passband of the fourth channel filter. ​ 3. The miniaturized planar quadripole according to claim 1, characterized in that, Each strip-line resonator of the first channel filter and each strip-line resonator of the third channel filter are arranged in parallel, and each strip-line resonator of the first channel filter is staggered by a half strip-line resonator width from a corresponding strip-line resonator of the third channel filter; Each strip-line resonator of the second channel filter and each strip-line resonator of the fourth channel filter are arranged in parallel, and each strip-line resonator of the second channel filter is staggered by a half strip-line resonator width from a corresponding strip-line resonator of the fourth channel filter; The third channel filter is arranged at the left side of the common strip-line resonator, and a right side stub of a first strip-line resonator of the first channel filter is arranged opposite to a left side stub of the common strip-line resonator; the fourth channel filter is arranged at the right side of the common strip-line resonator, and a left side stub of a first strip-line resonator of the second channel filter is arranged opposite to a right side stub of the common strip-line resonator.

4. The miniaturized planar quadripole according to claim 3, characterized in that, The strip-line resonator and the common strip-line resonator are both strip-line stepped-impedance resonators; an electric field of the strip-line stepped-impedance resonator is concentrated in an upper half of the strip-line stepped-impedance resonator, and a magnetic field of the strip-line stepped-impedance resonator is concentrated in a lower half of the strip-line stepped-impedance resonator.

5. The miniaturized planar quadripole according to claim 4, characterized in that, A right side stub of the first strip-line resonator of the first channel filter is electrically coupled to a left side stub of the common strip-line resonator, and a left side stub of the first strip-line resonator of the second channel filter is electrically coupled to a right side stub of the common strip-line resonator; A first strip-line resonator of the third channel filter is magnetically coupled to the common strip-line resonator, and a first strip-line resonator of the fourth channel filter is magnetically coupled to the common strip-line resonator.

6. The miniaturized planar quadripole according to claim 4, characterized in that, A right side stub of the first strip-line resonator of the first channel filter is electrically coupled to a left side stub of the common strip-line resonator, and a left side stub of the first strip-line resonator of the second channel filter is electrically coupled to a right side stub of the common strip-line resonator; A right side stub of the first strip-line resonator of the third channel filter is electrically coupled to a left side stub of the common strip-line resonator, and a first strip-line resonator of the fourth channel filter is magnetically coupled to the common strip-line resonator.

7. The miniaturized planar quadripole according to claim 4, characterized in that, A right side stub of the first strip-line resonator of the first channel filter is electrically coupled to a left side stub of the common strip-line resonator, and a left side stub of the first strip-line resonator of the second channel filter is electrically coupled to a right side stub of the common strip-line resonator; A right side stub of the first strip-line resonator of the third channel filter is electrically coupled to a left side stub of the common strip-line resonator, and a left side stub of the first strip-line resonator of the fourth channel filter is electrically coupled to a right side stub of the common strip-line resonator.

8. The miniaturized planar quadripole according to claim 4, characterized in that, The first band-line resonator of the first channel filter is magnetically coupled with the common band-line resonator, the first band-line resonator of the second channel filter is magnetically coupled with the common band-line resonator, the first band-line resonator of the third channel filter is magnetically coupled with the common band-line resonator, and the first band-line resonator of the fourth channel filter is magnetically coupled with the common band-line resonator.

9. The miniaturized planar quadripole according to any of claims 5-6, 8, characterized in that, The magnetic coupling is that the lower half of the two band-line resonators is connected by a reinforcing rib; the distance between the reinforcing rib and the bottom plate is proportional to the magnetic coupling strength between the two band-line resonators.

10. The miniaturized planar quadripole according to any one of claims 5 to 7, characterized in that, The electrical coupling is that the branches of the upper half of the two band-line resonators are isolated without obstacles; the distance between the branches of the upper half of the two band-line resonators is inversely proportional to the degree of electrical coupling between the two band-line resonators.

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