A microstrip-fed dielectric filter ring coupler

Abstract

The application discloses a microstrip feed-based dielectric filter ring coupler, and comprises a dielectric substrate, a dielectric resonator and a microstrip line structure. The application realizes a multi-mode dielectric resonator through the position arrangement of the dielectric resonator and the microstrip line structure. The multi-mode dielectric resonator is used as a resonant main body, and a single-layer plate microstrip line is used as a feed structure. Since the height requirement of the dielectric resonator is low, the coupler obtains an extremely low profile, forms an ultrathin dielectric filter ring coupler, maintains good filtering performance and low loss, and enables the coupler to be easily integrated with other planar circuits, thereby reducing the volume of the coupler. The application is widely applied to the technical field of dielectric circuits.

Description

Technical Field

[0001] This invention relates to the field of dielectric circuit technology, and in particular to a dielectric filter ring coupler based on microstrip feeding. Background Technology

[0002] With the rapid development of wireless communication technology, communication systems are placing higher demands on the miniaturization of key components. The integration of passive devices and filters is one of the most effective methods. For example, filter power dividers, filter antennas, and filter couplers have been proposed successively. Among them, the ring coupler is one of the key components in modern communication systems, capable of providing both in-phase and differential power distribution characteristics simultaneously. To suppress unwanted noise, two bandpass filters are usually added at the front or back of the ring coupler, which leads to a large circuit size and increases overall insertion loss. Summary of the Invention

[0003] To address the technical problem of balancing noise suppression, insertion loss, and size in current ring couplers, the present invention aims to provide a dielectric filter ring coupler based on microstrip feeding.

[0004] This invention includes a microstrip-fed dielectric filter ring coupler, wherein the microstrip-fed dielectric filter ring coupler comprises:

[0005] Dielectric substrate; the dielectric substrate includes an upper surface and a lower surface;

[0006] A dielectric resonator; the dielectric resonator is mounted on the upper surface, and the dielectric resonator is attached to the upper surface to form a contact surface. The cross-section of the dielectric resonator is hexagonal, and the second side, fourth side, and sixth side of the dielectric resonator are covered with metal layers, wherein the cross-section is a section parallel to the dielectric substrate, and the second side, the fourth side, and the sixth side are non-adjacent sides.

[0007] A microstrip line structure is disposed on the upper surface of the dielectric substrate. The microstrip line structure extends from the edge of the upper surface to the location of the dielectric resonator. A portion of the end of the microstrip line structure extends from a corresponding position on a first side of the dielectric resonator into the contact surface between the dielectric resonator and the upper surface. The first side is the side between the second side and the sixth side. Another portion of the end of the microstrip line structure is flush with the second side, the fourth side, and the sixth side, respectively.

[0008] Furthermore, the microstrip line structure includes a first part microstrip line, a second part microstrip line, a third part microstrip line, and a fourth part microstrip line;

[0009] One end of the first microstrip line is located at the edge of the upper surface, and the other end extends from the corresponding position of the first side of the dielectric resonator into the contact surface between the dielectric resonator and the upper surface.

[0010] One end of the second part of the microstrip line is located at the edge of the upper surface, and the other end is flush with the second side surface;

[0011] One end of the third microstrip line is located at the edge of the upper surface, and the other end is flush with the sixth side surface.

[0012] One end of the fourth microstrip line is located at the edge of the upper surface, and the other end is flush with the fourth side surface.

[0013] Furthermore, the first portion of the microstrip line includes a wider rectangular front section and a narrower rectangular rear section, wherein the front section and the rear section extend in a straight line, the front section extends from the edge of the upper surface to the first side surface, and the rear section is located at the contact surface between the dielectric resonator and the upper surface.

[0014] The second part of the microstrip line includes a wider rectangular front section and a narrower rectangular rear section, wherein the included angle between the front section and the rear section is an obtuse angle, the front section extends from the edge of the upper surface to the vertex between the second side and the third side, and the rear section extends along a direction flush with the second side to the vertex between the second side and the first side.

[0015] The third part of the microstrip line includes a wider rectangular front section and a narrower rectangular rear section, wherein the included angle between the front section and the rear section is an obtuse angle. The front section extends from the edge of the upper surface to the vertex between the sixth side and the fifth side, and the rear section extends along a direction flush with the sixth side to the vertex between the sixth side and the first side.

[0016] The fourth microstrip line includes a narrower rectangular front section, a rectangular middle section of the same width as the front section, and a widest rectangular rear section. The angle between the front and middle sections is a right angle. The middle and rear sections extend along a straight line. The front section extends from the edge of the upper surface to the interior of the upper surface and connects with the middle section. The middle section extends to the vertex between the fourth and fifth side surfaces and connects with the rear section. The rear section extends along a direction flush with the fourth side surface to the vertex between the fourth and third side surfaces.

[0017] Furthermore, the microstrip-fed dielectric filter ring coupler also includes:

[0018] First SMA connector; the first SMA connector is connected to one end of the first portion of the microstrip line located at the edge of the upper surface;

[0019] Second SMA connector; the second SMA connector is connected to one end of the second portion of the microstrip line located at the edge of the upper surface;

[0020] The third SMA connector is connected to one end of the third microstrip line located at the edge of the upper surface.

[0021] The fourth SMA connector is connected to one end of the fourth microstrip line located on the edge of the upper surface.

[0022] The second SMA connector and the third SMA connector serve as the output terminals of the dielectric filter ring coupler.

[0023] Furthermore, the dielectric substrate and the dielectric resonator are respectively provided with corresponding through holes. The dielectric filter ring coupler based on microstrip feeding also includes a plastic screw, which passes through the through holes of the dielectric substrate and the dielectric resonator, thereby fixing the dielectric resonator to the dielectric substrate.

[0024] Furthermore, the entire lower surface is covered with a metal material as a grounding plate.

[0025] Furthermore, the metal layers applied to the second side, the fourth side, and the sixth side have gaps between them and the contact surfaces that adhere to the dielectric resonator and the upper surface.

[0026] Furthermore, the ground plane is made of copper, and the metal layer is made of silver or copper.

[0027] Furthermore, the microstrip-fed dielectric filter ring coupler also includes:

[0028] The top cover is used to cover the dielectric substrate on one side of the upper surface, forming a shielding cavity with the dielectric substrate, so that the dielectric resonator and the microstrip line structure are located inside the shielding cavity.

[0029] Furthermore, the top cover is made of copper.

[0030] The beneficial effects of this invention are as follows: The microstrip-fed dielectric filter ring coupler in the embodiments realizes a multimode dielectric resonator through the size and shape design of the dielectric resonator and the position arrangement of the side metal layer; by using the multimode dielectric resonator as the resonant body and using a single-layer microstrip line as the feeding structure, the coupler obtains an extremely low profile due to the low height requirement of the dielectric resonator, forming an ultra-thin dielectric filter ring coupler. While maintaining good filtering performance and low loss, the coupler can be easily integrated with other planar circuits, thereby reducing the size of the coupler. Attached Figure Description

[0031] Figure 1 This is a schematic diagram of the structure of the dielectric filter ring coupler based on microstrip feeding in the embodiment;

[0032] Figure 2 This is a cross-sectional view of the dielectric filter ring coupler based on microstrip feeding in the embodiment;

[0033] Figure 3 This is a top view of the dielectric filter ring coupler based on microstrip feeding in the embodiment;

[0034] Figure 4 This is a schematic diagram of the structure of each part of the microstrip line in the embodiment;

[0035] Figure 5 This is a schematic diagram showing the installation positions of each SMA connector in the embodiment;

[0036] Figure 6 This is a schematic diagram showing the simulation and measured results of the dielectric filter ring coupler in the in-phase output mode in the embodiment.

[0037] Figure 7 This is a schematic diagram showing the simulation and measurement results of the dielectric filter ring coupler in differential output mode in the embodiment.

[0038] Figure 8 This is a schematic diagram showing the simulation and measured results of the return loss and isolation of the two output ports and the isolation of the two input ports of the dielectric filter ring coupler in the embodiment.

[0039] Figure 9 This is a schematic diagram showing the simulation and measured results of the phase difference between the two output ports of the dielectric filter ring coupler in both in-phase and differential output modes in the embodiment.

[0040] Reference numerals: 100—Dielectric substrate, 101—Ground plane, 200—Microstrip line structure, 201—First section of microstrip line, 202—Second section of microstrip line, 203—Third section of microstrip line, 204—Fourth section of microstrip line, 300—Dielectric resonator, 301—First side, 302—Second side, 303—Third side, 304—Fourth side, 305—Fifth side, 306—Sixth side, 401—First SMA connector, 402—Second SMA connector, 403—Third SMA connector, 404—Fourth SMA connector, 500—Top cover. Detailed Implementation

[0041] The challenge of balancing noise suppression, insertion loss, and size in ring couplers can be addressed by integrating filtering functionality within the ring coupler. Couplers based on the dielectric resonator 300 exhibit high quality factor, small size, and high temperature stability, meeting the development needs of future wireless communication systems and possessing broad application prospects. However, implementing a ring coupler based on the dielectric resonator 300 by feeding the high-profile dielectric resonator 300 using a coaxial probe presents integration difficulties. Compared to coaxial probes, microstrip feeding methods allow for easier integration with other circuits.

[0042] Based on the above principles, this embodiment provides a dielectric filter ring coupler based on microstrip feeding.

[0043] In this embodiment, the structure of the microstrip-fed dielectric filter ring coupler is as follows: Figure 1 As shown, a cross-sectional view of a microstrip-fed dielectric filter ring coupler is presented. Figure 2 As shown, a top view of the microstrip-fed dielectric filter ring coupler is as follows. Figure 3 As shown.

[0044] Reference Figure 1 The microstrip-fed dielectric filter ring coupler includes a dielectric substrate 100, a dielectric resonator 300, and a microstrip line structure 200.

[0045] The dielectric substrate 100 is a rectangular thin plate made of Rogers RT / Duroid material with a thickness of 0.508 mm and a dielectric constant of 3.38. The "upper surface" and "lower surface" of the dielectric substrate 100 are only used to distinguish the two surfaces of the dielectric substrate 100 and do not mean that the "upper surface" must face upward or the "lower surface" must face downward when the dielectric filter ring coupler of the present invention is working.

[0046] In this embodiment, the dielectric resonator 300 can be made of high-dielectric ceramic material. The dielectric resonator 300 is formed by cutting a preform and sintering it at high temperature, or it can be fabricated using ceramic 3D printing technology. (Refer to...) Figure 1 , Figure 2 and Figure 3 The dielectric resonator 300 is hexagonal in shape, meaning its cross-section (parallel to the dielectric substrate 100) is hexagonal. The dielectric resonator 300 is mounted on the upper surface, and the dielectric resonator 300 is in contact with the upper surface. (Refer to...) Figure 1 and Figure 2Both the dielectric substrate 100 and the dielectric resonator 300 contain through holes in the middle, and the dielectric resonator 300 can be mounted on the upper surface of the dielectric substrate 100 by screws made of insulating materials such as plastic through the through holes.

[0047] Reference Figure 1 and Figure 3 The dielectric resonator 300 includes a first side 301, a second side 302, a third side 303, a fourth side 304, a fifth side 305, and a sixth side 306 that are sequentially adjacent, wherein the second side 302, the fourth side 304, and the sixth side 306 are non-adjacent sides.

[0048] A metal layer, such as silver or copper, is applied to the second side 302, the fourth side 304, and the sixth side 306, respectively. A gap is left between the metal layer on each side and the contact surface between the dielectric resonator 300 and the upper surface to prevent the metal layer from communicating with the upper surface.

[0049] In this embodiment, a microstrip line structure 200 can be fabricated on the upper surface of the dielectric substrate 100 using printed circuit technology, and the entire lower surface of the dielectric substrate 100 can be covered with metal as a ground plane 101. Both the microstrip line structure 200 and the ground plane 101 are made of metal, for example, both the microstrip line structure 200 and the ground plane 101 can be made of copper.

[0050] Reference Figure 1 and Figure 3 The microstrip line structure 200 is disposed on the upper surface of the dielectric substrate 100. Specifically, the microstrip line structure 200 extends from the edge of the upper surface to the location of the dielectric resonator 300. A portion of the end of the microstrip line structure 200 extends from the corresponding position of the first side 301 of the dielectric resonator 300 into the contact surface between the dielectric resonator 300 and the upper surface. The first side 301 is the side between the second side 302 and the sixth side 306. The other portion of the end of the microstrip line structure 200 is flush with the second side 302, the fourth side 304 and the sixth side 306, respectively.

[0051] Specifically, refer to Figure 1 and Figure 3The microstrip line structure 200 includes four parts: a first microstrip line 201, a second microstrip line 202, a third microstrip line 203, and a fourth microstrip line 204. One end of the first microstrip line 201 is located at the edge of the upper surface, and the other end extends from the corresponding position of the first side 301 of the dielectric resonator 300 into the contact surface between the dielectric resonator 300 and the upper surface. One end of the second microstrip line 202 is located at the edge of the upper surface, and the other end is flush with the second side 302. One end of the third microstrip line 203 is located at the edge of the upper surface, and the other end is flush with the sixth side 306. One end of the fourth microstrip line 204 is located at the edge of the upper surface, and the other end is flush with the fourth side 304. The ends of the first, second, third, and fourth microstrip lines 201, 202, 203, and 204 located at the edge of the upper surface are aligned with the edge of the upper surface.

[0052] In this embodiment, the structures of the first microstrip line 201, the second microstrip line 202, the third microstrip line 203, and the fourth microstrip line 204 are as follows: Figure 4 As shown. (Refer to...) Figure 4The first microstrip line 201 comprises a wider rectangular front section and a narrower rectangular rear section, wherein the front and rear sections extend in a straight line. The front section extends from the edge of the upper surface to the first side surface 301, and the rear section is located at the contact surface between the dielectric resonator 300 and the upper surface. The second microstrip line 202 comprises a wider rectangular front section and a narrower rectangular rear section, wherein the angle between the front and rear sections is an obtuse angle, thus forming a "√" shaped structure. The front section extends from the edge of the upper surface to the vertex between the second side surface 302 and the third side surface 303, and the rear section extends along a direction flush with the second side surface 302 to the vertex between the second side surface 302 and the first side surface 301. The third microstrip line 203 comprises a wider rectangular front section and a narrower rectangular rear section, wherein the angle between the front and rear sections is an obtuse angle, thus forming a "√" shaped structure. The front section extends from the edge of the upper surface to the sixth side surface. The vertex between side 306 and the fifth side 305, and the rear section extends along a direction flush with the sixth side 306 to the vertex between the sixth side 306 and the first side 301. Therefore, the structure of the third part microstrip line 203 is the same as the structure of the second part microstrip line 202, and the position of the third part microstrip line 203 is symmetrical with the position of the second part microstrip line 202. The fourth part microstrip line 204 includes a narrower rectangular front section, a wider rectangular middle section, and a widest rectangular rear section. The angle between the front section and the middle section is a right angle, thus forming an "L" shaped structure. The middle section and the rear section extend along a straight line. The front section extends from the edge of the upper surface to the interior of the upper surface and connects with the middle section. The middle section extends to the vertex between the fourth side 304 and the fifth side 305 and connects with the rear section. The rear section extends along a direction flush with the fourth side 304 to the vertex between the fourth side 304 and the third side 303.

[0053] In this embodiment, when using a microstrip-fed dielectric filter ring coupler, reference can be made to... Figure 5 A first SMA connector 401, a second SMA connector 402, a third SMA connector 403, and a fourth SMA connector 404 are mounted at corresponding positions on the dielectric substrate 100. (Refer to...) Figure 5 The first SMA connector 401 is connected to one end of the upper surface edge of the first microstrip line 201, the second SMA connector 402 is connected to one end of the upper surface edge of the second microstrip line 202, the third SMA connector 403 is connected to one end of the upper surface edge of the third microstrip line 203, and the fourth SMA connector 404 is connected to one end of the upper surface edge of the fourth microstrip line 204.

[0054] The first SMA connector 401, the second SMA connector 402, the third SMA connector 403, and the fourth SMA connector 404 each include a metal probe, which is connected to one end of the corresponding microstrip line. This metal probe can be connected to an external signal source and / or signal receiver, allowing the signal source and / or signal receiver to be connected to a dielectric filter ring coupler via the metal probe, thereby transmitting and receiving signals.

[0055] In this embodiment, the working principle of the filter ring coupler is as follows: by metallizing part of the side of the hexagonal dielectric resonator 300, a three-mode dielectric resonator 300 is obtained. The three-mode dielectric resonator 300 can operate in three modes respectively named M1, M2, and M3. The positions of each part of the microstrip line are adapted to the electromagnetic field distribution characteristics of these modes, so that the first part of the microstrip line 201 (first SMA connector 401) can excite mode M1, the second part of the microstrip line 202 (second SMA connector 402) serves as the output terminal, thereby achieving the required 0° phase difference, and the third part of the microstrip line 203 serves as the common output terminal, thereby achieving the required 180° phase difference. Then, the fourth part of the microstrip line 204 (fourth SMA connector 404) is used to excite modes M2 and M3. By introducing coupling between the source and the load, transmission zeros are obtained on both sides of the in-phase passband and the differential passband, achieving good filtering performance of the coupler.

[0056] In this embodiment, refer to Figure 1 and Figure 2 The microstrip-fed dielectric filter ring coupler also has a top cover 500, which can be made of copper. Multiple threaded holes can be provided on the side walls and bottom of the metal shielding cavity to fix the dielectric substrate 100 and the SMA connector.

[0057] Reference Figure 2 When the upper surface of the dielectric substrate 100 faces upwards, the dielectric filter, from top to bottom, consists of an upper cover 500, a dielectric resonator 300, a microstrip line structure 200, the dielectric substrate 100, and a ground plane 101. (Refer to...) Figure 1 The upper cover 500 covers the dielectric substrate 100 on one side of the upper surface, thereby forming a shielding cavity with the dielectric substrate 100, so that the dielectric resonator 300 and the microstrip line structure 200 are located in the shielding cavity, further improving the filtering performance of the coupler.

[0058] In this embodiment, refer to Figure 1 , Figure 2 , Figure 3 The dielectric substrate 100 has a length and width of A and B, respectively, and the dielectric resonator 300 has a height of h and a side length of l. 23The gap height between the side metal layer and the bottom of the dielectric resonator 300 is h0, and the length and width of the first part of the microstrip line 201 are l and l, respectively. 41 l 42 and w 41 w 42 The length and width of the second part, microstrip line 202, are l and l respectively. 21 l 22 , l23 and w 21 w 22 The dimensions of the third microstrip line 203 are exactly the same as those of the second microstrip line 202, and the length and width of the fourth microstrip line 204 are l and l respectively. 11 l 12 l 13 and w 11 w 12 The distance between the center of the positioning through hole and the center of the dielectric resonator 300 is d, and the radius of the positioning through hole is r1.

[0059] In this embodiment, the design process for the dimensions of the above parameters is as follows: First, based on the required center frequency (5.8GHz in this embodiment) and 3dB relative bandwidth (6.2% in this embodiment), and the relevant parameters of the dielectric substrate 100 (relative permittivity of 3.38 and thickness of 0.508mm in this embodiment), simulations are performed to determine the height h and side length l of the dielectric resonator 300 so that the frequencies of the three modes of the dielectric resonator 300 are distributed within the same passband. 23 And tuning is performed using the height h0 of the gap at the bottom of the side metal layer; then, the width w of the portion of the microstrip line structure 200 that contacts the dielectric resonator 300 is adjusted. 11 w 12 w 22 w 42 Impedance matching is achieved by adjusting the length l of the corresponding microstrip line. 13 l 22 l 42 This controls the input / output coupling coefficient. The appropriate microstrip line length is selected based on the length of the metal probes of the external SMA connector. 11 l 21 l 41 This determines the length A and width B of the dielectric substrate 100. Secondly, based on the requirement of 50 ohms impedance matching at the input and output terminals at the center frequency, the width w of a portion of the microstrip line is determined. 11 w 21 w 41 Finally, based on the degree of influence of the through-hole on the coupler performance, a suitable through-hole position d and radius r1 are selected.

[0060] Based on the above analysis, in this embodiment, the parameters are set to the following values: A = 26mm, B = 26mm, h = 1.7mm, h0 = 0.1mm, l 11 =4.3mm,l 12 =4.5mm,l 13 =8.8mm,w 11 =1mm,w 12 =1.1mm,l 21 =4.4mm,l 22 =1.4mm,l 23 =7.5mm,w 21 =1.2mm,w 22 =0.3mm,l 41 =5.1mm,l 42 =6.8mm,w 41 =1.2mm,w 42 =1mm, d=1mm, r1=0.6mm.

[0061] Based on the above values, dielectric substrates, dielectric resonators, and microstrip line structures of corresponding dimensions were fabricated. Simulations were performed on these values, and the fabricated dielectric filter ring coupler was experimentally tested. The simulation and experimental results are as follows: Figures 6-9 As shown.

[0062] Simulation and experimental results for a dielectric filter ring coupler in in-phase output mode are as follows: Figure 6 As shown in the figure. Solid lines represent measured data, and dashed lines represent simulated data. In this example, the measured center frequency of the coupler in in-phase output mode is 5.82 GHz; the simulated 3dB bandwidth is 6%, and the measured 3dB bandwidth is 6.5%; the simulated minimum loss is 0.45 dB, and the measured minimum loss is 0.7 dB; the return loss in the passband is 20 dB in both simulation and measurement. There is a transmission zero on both the left and right sides of the passband in both simulation and measurement.

[0063] Simulation and experimental results for the dielectric filter ring coupler in differential output mode are as follows: Figure 7 As shown in the figure. Solid lines represent measured data, and dashed lines represent simulated data. In this example, the measured center frequency of the coupler in differential output mode is 5.82 GHz; the simulated 3dB bandwidth is 6%, and the measured 3dB bandwidth is 6.2%; the simulated minimum loss is 0.75 dB, and the measured minimum loss is 0.92 dB; the simulated passband return loss is 20 dB, and the measured passband return loss is 22 dB. Both the simulated and measured passbands have a transmission zero on each side.

[0064] The simulation and measured results of the return loss and isolation of the two output ports and the isolation of the two input ports of the dielectric filter ring coupler in this example are as follows: Figure 8As shown in the figure. Solid lines represent measured data, and dashed lines represent simulated data. In this example, the measured and simulated passband return loss of the two output ports of the coupler is 20dB; the simulated passband isolation of the two output ports is 15dB, and the measured passband isolation is 21dB; the simulated passband isolation of the two input ports is 25dB, and the measured passband isolation is 30dB.

[0065] In this example, the simulation and measured results of the phase difference between the two output ports of the dielectric filter ring coupler in both in-phase and differential output modes are as follows: Figure 9 As shown. In in-phase output mode, the measured phase difference between the two output ports is ±2.5°, and in differential output mode, the measured phase difference between the two output ports is ±3°.

[0066] All the above results were obtained using a vector network analyzer. The comparison between the simulation and test results shows that the simulated and measured curves are in good agreement, demonstrating the feasibility of the proposed solution. The offset mainly originates from the relative permittivity deviation of the processed dielectric resonator material and factors such as installation position deviation. With improvements in processing technology and installation alignment accuracy, the simulation and measured results can be made even closer.

[0067] It should be noted that, unless otherwise specified, when a feature is referred to as "fixed" or "connected" to another feature, it can be directly fixed or connected to the other feature, or indirectly fixed or connected to the other feature. Furthermore, the descriptions of "upper," "lower," "left," and "right" used in this disclosure are only relative to the relative positional relationships of the components of this disclosure in the accompanying drawings. The singular forms "a," "an," and "the" used in this disclosure are also intended to include the plural forms, unless the context clearly indicates otherwise. Moreover, unless otherwise defined, all technical and scientific terms used in this embodiment have the same meaning as commonly understood by one of ordinary skill in the art. The terminology used in this embodiment specification is only for describing particular embodiments and is not intended to limit the invention. The term "and / or" as used in this embodiment includes any combination of one or more of the associated listed items.

[0068] It should be understood that although the terms first, second, third, etc., may be used to describe various elements in this disclosure, these elements should not be limited to these terms. These terms are only used to distinguish elements of the same type from each other. For example, a first element may also be referred to as a second element without departing from the scope of this disclosure, and similarly, a second element may also be referred to as a first element. The use of any and all instances or exemplary language (“e.g.,” “such as,” etc.) provided in this embodiment is intended only to better illustrate embodiments of the invention and, unless otherwise required, does not impose a limitation on the scope of the invention.

[0069] The above are merely preferred embodiments of the present invention. The present invention is not limited to the above-described embodiments. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention, as long as they achieve the technical effects of the present invention by the same means, should be included within the scope of protection of the present invention. Within the scope of protection of the present invention, the technical solutions and / or implementation methods can have various modifications and variations.

Claims

1. A dielectric filter ring coupler based on microstrip feeding, characterized in that, The microstrip-fed dielectric filter ring coupler includes: Dielectric substrate; the dielectric substrate includes an upper surface and a lower surface; A dielectric resonator; the dielectric resonator is mounted on the upper surface, and the dielectric resonator is attached to the upper surface to form a contact surface. The cross-section of the dielectric resonator is hexagonal, and the second side, fourth side, and sixth side of the dielectric resonator are covered with metal layers, wherein the cross-section is a section parallel to the dielectric substrate, and the second side, the fourth side, and the sixth side are non-adjacent sides. A microstrip line structure is disposed on the upper surface of the dielectric substrate. The microstrip line structure extends from the edge of the upper surface to the location of the dielectric resonator. A portion of the end of the microstrip line structure extends from a corresponding position on a first side of the dielectric resonator into the contact surface between the dielectric resonator and the upper surface. The first side is the side between the second side and the sixth side. Another portion of the end of the microstrip line structure is flush with the second side, the fourth side, and the sixth side, respectively.

2. The microstrip-fed dielectric filter ring coupler according to claim 1, characterized in that: The microstrip line structure includes a first part microstrip line, a second part microstrip line, a third part microstrip line, and a fourth part microstrip line; One end of the first microstrip line is located at the edge of the upper surface, and the other end extends from the corresponding position of the first side of the dielectric resonator into the contact surface between the dielectric resonator and the upper surface. One end of the second part of the microstrip line is located at the edge of the upper surface, and the other end is flush with the second side surface; One end of the third microstrip line is located at the edge of the upper surface, and the other end is flush with the sixth side surface. One end of the fourth microstrip line is located at the edge of the upper surface, and the other end is flush with the fourth side surface.

3. The microstrip-fed dielectric filter ring coupler according to claim 2, characterized in that: The first portion of the microstrip line includes a wider rectangular front section and a narrower rectangular rear section, wherein the front and rear sections extend in a straight line, the front section extends from the edge of the upper surface to the first side surface, and the rear section is located at the contact surface between the dielectric resonator and the upper surface. The second part of the microstrip line includes a wider rectangular front section and a narrower rectangular rear section, wherein the included angle between the front section and the rear section is an obtuse angle, the front section extends from the edge of the upper surface to the vertex between the second side and the third side, and the rear section extends along a direction flush with the second side to the vertex between the second side and the first side. The third part of the microstrip line includes a wider rectangular front section and a narrower rectangular rear section, wherein the included angle between the front section and the rear section is an obtuse angle. The front section extends from the edge of the upper surface to the vertex between the sixth side and the fifth side, and the rear section extends along a direction flush with the sixth side to the vertex between the sixth side and the first side. The fourth microstrip line includes a narrower rectangular front section, a rectangular middle section of the same width as the front section, and a widest rectangular rear section. The angle between the front and middle sections is a right angle. The middle and rear sections extend along a straight line. The front section extends from the edge of the upper surface to the interior of the upper surface and connects with the middle section. The middle section extends to the vertex between the fourth and fifth side surfaces and connects with the rear section. The rear section extends along a direction flush with the fourth side surface to the vertex between the fourth and third side surfaces.

4. The microstrip-fed dielectric filter ring coupler according to claim 2, characterized in that, The microstrip-fed dielectric filter ring coupler further includes: First SMA connector; the first SMA connector is connected to one end of the first portion of the microstrip line located at the edge of the upper surface; Second SMA connector; the second SMA connector is connected to one end of the second portion of the microstrip line located at the edge of the upper surface; The third SMA connector is connected to one end of the third microstrip line located at the edge of the upper surface. The fourth SMA connector is connected to one end of the fourth microstrip line located on the edge of the upper surface. The second SMA connector and the third SMA connector serve as the output terminals of the dielectric filter ring coupler.

5. The microstrip-fed dielectric filter ring coupler according to claim 1, characterized in that, The dielectric substrate and the dielectric resonator are respectively provided with corresponding through holes. The dielectric filter ring coupler based on microstrip feeding also includes a plastic screw, which passes through the through holes of the dielectric substrate and the dielectric resonator, thereby fixing the dielectric resonator to the dielectric substrate.

6. The microstrip-fed dielectric filter ring coupler according to claim 1, characterized in that, The entire lower surface is covered with metal material as a grounding plate.

7. The microstrip-fed dielectric filter ring coupler according to claim 6, characterized in that, The metal layers applied to the second, fourth, and sixth sides have gaps between them and the contact surfaces that fit the dielectric resonator and the upper surface.

8. The microstrip-fed dielectric filter ring coupler according to claim 7, characterized in that, The ground plane is made of copper, and the metal layer is made of silver or copper.

9. The microstrip-fed dielectric filter ring coupler according to any one of claims 1-8, characterized in that, The microstrip-fed dielectric filter ring coupler further includes: The top cover is used to cover the dielectric substrate on one side of the upper surface, forming a shielding cavity with the dielectric substrate, so that the dielectric resonator and the microstrip line structure are located inside the shielding cavity.

10. The microstrip-fed dielectric filter ring coupler according to claim 9, characterized in that, The top cover is made of copper.

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