WO2022198931A1

WO2022198931A1 - Single-layer broadband microstrip patch antenna and method for forming same

Info

Publication number: WO2022198931A1
Application number: PCT/CN2021/117399
Authority: WO
Inventors: 徐海鹏; 李艳; 齐望东; 黄永明; 潘孟冠; 李晓东
Original assignee: 网络通信与安全紫金山实验室
Priority date: 2021-03-25
Filing date: 2021-09-09
Publication date: 2022-09-29
Also published as: CN112713404A; CN112713404B

Abstract

The present application relates to a single-layer broadband microstrip patch antenna and a method for forming same. The single-layer broadband microstrip patch antenna comprises: a single-layer dielectric substrate and an antenna unit. Metal layers are coated on the front surface and the back surface of the single-layer dielectric substrate. The metal layer on the back surface of the single-layer dielectric substrate is a metal ground. The metal layer on the front surface of the single-layer dielectric substrate is etched into the antenna unit. The antenna unit comprises a radiation patch, a first resonant cavity, a second resonant cavity, a grounding short-circuit pin, and a microstrip transmission line. Gaps are provided on two opposite sides of the center of the radiation patch. The gaps are centrally symmetric with the center of the radiation patch.

Description

Single-layer broadband microstrip patch antenna and method for forming single-layer broadband microstrip patch antenna

CROSS-REFERENCE TO RELATED APPLICATIONS

This application claims the Chinese application titled "Single-layer Broadband Microstrip Patch Antenna", filed on March 25, 2021, with application number 2021103166598, the disclosure of which is fully incorporated into this application by reference.

technical field

The present application relates to the technical field of wireless communication, and in particular, to a single-layer broadband microstrip patch antenna and a method for forming a single-layer broadband microstrip patch antenna.

Background technique

As the carrier of transmitting and receiving information in a wireless communication system, the antenna is one of the key components in the wireless communication system, and its performance directly affects the technical indicators of the wireless communication system.

Among many types of antennas, microstrip patch antennas have many advantages, such as light weight, small size, low profile, easy integration with RF circuits, high processing accuracy, and suitability for rapid industrial mass production. Therefore, microstrip patch antennas and microstrip patch antennas with variable structures have been widely used in wireless communication systems.

SUMMARY OF THE INVENTION

The present application provides a single-layer broadband microstrip patch antenna.

The embodiment of the present application provides a single-layer broadband microstrip patch antenna, the single-layer broadband microstrip patch antenna includes: a single-layer dielectric substrate and an antenna unit; the front and back of the single-layer dielectric substrate are covered with A metal layer, the metal layer on the back of the single-layer dielectric substrate is a metal ground; the metal layer on the front of the single-layer dielectric substrate is etched to form an antenna unit, and the antenna unit includes a radiation patch, a first resonant cavity, a second resonant cavity, a grounding short-circuit pin and a microstrip transmission line; the center of the radiation patch is provided with slits on opposite sides, the slits are centrally symmetric with the center of the radiation patch, and the The slits include a slot-shaped slot, each of the slot-shaped slots includes two opposite first slots and a second slot connecting the ends on the same side of the two first slots to communicate with the two first slots, and the slot-shaped slots The first slot of the slot is parallel to the non-radiating side of the radiation patch, and the two first slots of the indented slot are parallel to the radiating side of the radiation patch; the first resonant cavity is parallel to the second The resonant cavity is connected; the ground short-circuit pin is arranged in the middle of the connected first resonant cavity and the second resonant cavity, and is short-circuited to connect the first resonant cavity and the metal ground; the microstrip transmission line is connected to the The first resonant cavity and the second resonant cavity are connected.

Embodiments of the present application also provide a method for forming a single-layer broadband microstrip patch antenna, including: providing a single-layer dielectric substrate, the front and back of the single-layer dielectric substrate are covered with metal layers, and the single-layer dielectric substrate is covered with metal layers. The metal layer on the back of the dielectric substrate is metal ground; the metal layer on the front of the single-layer dielectric substrate is etched to form an antenna unit, the antenna unit includes a radiation patch, a first resonant cavity, a second resonator cavity, grounding shorting pin and microstrip transmission line; etching a rectangular slot in the radiation patch; setting a rectangular patch in the radiation patch with the rectangular slot, one end of the rectangular patch is connected to the One of the radiating sides of the radiation patch is connected, and the other end penetrates the radiation patch and is connected with the other radiating side of the radiation patch; the symmetrical axis of the rectangle formed by the rectangular slit, The symmetry axis of the radiation patch coincides with the symmetry axis of the rectangular patch; wherein, the first resonant cavity is connected to the second resonant cavity; the ground short-circuit pin is arranged on the connected first resonator The middle of the cavity and the second resonant cavity is short-circuited to connect the first resonant cavity and the metal ground; the microstrip transmission line is connected to the first resonant cavity and the second resonant cavity.

The details of one or more embodiments of the invention are set forth in the accompanying drawings and the description below. Other features, objects and advantages of the present invention will become apparent from the description, drawings and claims.

Description of drawings

In order to more clearly illustrate the technical solutions in the embodiments of the present application or in the traditional technology, the following briefly introduces the accompanying drawings that are used in the description of the embodiments or the traditional technology. Obviously, the drawings in the following description are only the For some embodiments of the application, for those of ordinary skill in the art, other drawings can also be obtained according to these drawings without any creative effort.

1 is a schematic diagram of a side structure of a single-layer broadband microstrip patch antenna in one embodiment;

2 is a schematic diagram of a single-slot structure of a single-layer broadband microstrip patch antenna in one embodiment;

3 is a schematic diagram of a double-slit structure of a single-layer broadband microstrip patch antenna in one embodiment;

4 is a schematic diagram of a multi-slot structure of a single-layer broadband microstrip patch antenna in one embodiment;

5 is a schematic diagram of a side structure of a single-layer broadband microstrip patch antenna in one embodiment;

Fig. 6 is the S11 parameter diagram of the single-layer broadband microstrip patch antenna in one embodiment;

7 is an azimuth plane gain pattern of a single-layer broadband microstrip patch antenna at a frequency of 2.6G according to an embodiment;

FIG. 8 is an elevation gain pattern of a single-layer broadband microstrip patch antenna at a frequency of 2.6G according to an embodiment.

Reference numeral description: 100, patch antenna; 102, single-layer dielectric substrate; 104, antenna unit; 1040, radiation patch; 10402, single-slot radiation patch; 10404, double-slot radiation patch; patch; 1042, first resonant cavity; 1044, second resonant cavity; 1046, grounding short pin; 1048, microstrip transmission line; 106, radio frequency connector; 1050, rectangular patch; 111, first slot; 112, first Two gaps.

Detailed ways

In order to facilitate understanding of the present application, the present application will be described more fully below with reference to the related drawings. Embodiments of the present application are presented in the accompanying drawings. However, the application may be implemented in many different forms and is not limited to the embodiments described herein. Rather, these embodiments are provided so that this disclosure will be thorough and complete.

Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the technical field to which this application belongs. The terms used herein in the specification of the application are for the purpose of describing specific embodiments only, and are not intended to limit the application.

It will be understood that the terms "first", "second", etc. used in this application may be used herein to describe various elements, but these elements are not limited by these terms. These terms are only used to distinguish a first element from another element. For example, a first resistance may be referred to as a second resistance, and similarly, a second resistance may be referred to as a first resistance, without departing from the scope of this application. Both the first resistor and the second resistor are resistors, but they are not the same resistor.

It can be understood that the "connection" in the following embodiments should be understood as "electrical connection", "communication connection", etc. if the connected circuits, modules, units, etc. have electrical signals or data transmission between them.

As used herein, the singular forms "a," "an," and "the/the" can include the plural forms as well, unless the context clearly dictates otherwise. It should also be understood that the terms "comprising/comprising" or "having" etc. designate the presence of stated features, integers, steps, operations, components, parts or combinations thereof, but do not preclude the presence or addition of one or more Possibilities of other features, integers, steps, operations, components, parts or combinations thereof. Also, as used in this specification, the term "and/or" includes any and all combinations of the associated listed items.

At present, the global wireless communication system has entered the 5G era. The research and development cycle of wireless communication systems from the 1G to 5G era is getting shorter and shorter. The wireless communication system has developed from the simple voice function in the early stage to the function of text, picture, high-definition video, and may generally have the function of VR and AR in the future.

Antennas are key components in wireless communication systems. Microstrip patch antennas are widely used due to their many advantages. However, because the working mechanism of the microstrip patch antenna is a resonant antenna, its frequency bandwidth is extremely narrow, and the bandwidth of a common single-layer microstrip patch antenna is about 1%-2%. Therefore, the narrow-band characteristics of ordinary microstrip patch antennas seriously restrict its application range and cannot meet the needs of most practical application scenarios.

For the narrowband characteristics of microstrip patch antennas, domestic and foreign researchers have done a lot of research work. Based on the resonant working mechanism of the microstrip patch antenna, the most basic method to increase the bandwidth of the microstrip patch antenna is to reduce the quality factor of the antenna. From the perspective of the physical parameters of the antenna, it is to increase the thickness of the microstrip patch antenna dielectric substrate and reduce the The dielectric constant of the antenna dielectric substrate and the ratio of increasing the width of the radiating side to the non-radiating side of the patch antenna. Another method to widen the bandwidth of the microstrip patch antenna is the multi-resonance technology, that is, to change the single resonance of the microstrip patch antenna to multi-resonance. The parasitic coupling method, the method of adding adjustment branches to the feeding transmission line, the method of adding a matching network between the feeding transmission line and the patch antenna, the method of using capacitive coupling feeding, or the method of using a quarter or half resonator coupling feed electrical method.

As shown in FIG. 1 , in one embodiment of the present application, a single-layer broadband microstrip patch antenna 100 is provided. The single-layer broadband microstrip patch antenna 100 includes: a single-layer dielectric substrate 102 and an antenna unit 104; the front and back of the single-layer dielectric substrate 102 are covered with a metal layer, wherein the metal layer may be a copper-clad layer or a gold-clad layer, etc., The following description is given by taking the metal layer as the copper clad layer as an example. The copper clad layer on the backside of the single-layer dielectric substrate 102 is a metal ground; the copper clad layer on the front side of the single-layer dielectric substrate 102 is etched to form the antenna unit 104 . The front surface of the single-layer dielectric substrate 102 refers to the surface on which the antenna unit 104 is formed, and the rear surface of the single-layer dielectric substrate 102 refers to the other surface of the single-layer dielectric substrate 102 opposite to the front surface.

Specifically, the front and back surfaces of the single-layer dielectric substrate 102 are provided with copper clad layers, and the copper clad layer on the back of the single-layer dielectric substrate 102 serves as a metal ground; the copper clad layer on the front side of the single-layer dielectric substrate 102 is etched to form Antenna unit 104 . An intermediate medium is formed between the copper clad layer on the front side of the single-layer dielectric substrate 102 and the copper clad layer on the back side. The intermediate medium can be a general-purpose PCB processing board with uniform dielectric constant and basically the same thickness. In this embodiment, the single-layer dielectric substrate 102 is selected so that the cross-sectional height of the patch antenna 100 is low, the overall thickness is reduced, and the volume is reduced to facilitate integration. The antenna unit 104 is formed by etching the copper clad layer on the front surface of the layered dielectric substrate, so that the processing of the patch antenna 100 is simpler.

Please continue to refer to FIG. 1 , further, the antenna unit 104 includes a radiation patch 1040 , a first resonant cavity 1042 , a second resonant cavity 1044 , a ground short-circuit pin 1046 and a microstrip transmission line 1048 ; two opposite sides of the center of the radiation patch 1040 All of them are provided with slits, and the slits are symmetrical with the center of the radiation patch 1040 . The slits include indented slits, and each indented slit includes two opposite first slits 111 and a second slit 112 connecting the ends on the same side of the two first slits 111 to communicate with the two first slits 111 . The length of the two first slits 111 of the indented slit is the same, and the length of each of the two first slits 111 is smaller than the length of the second slit 112 . Radiating patch 1040 includes two opposing radiating edges and two opposing non-radiating edges. The second slot 112 of the indented slot is parallel to the non-radiating side of the radiation patch 1040 , and the two first slots 111 of the indented slot are parallel to the radiating edge of the radiation patch 1040 .

The above-mentioned single-layer broadband microstrip patch antenna 100 has slits on opposite sides of the center of the radiation patch 1040 , the slits are symmetrical with the center of the radiation patch 1040 , and the slits include splay-shaped slits. Each of the indented slits includes two opposite first slits 111 and a second slit 112 connecting ends on the same side of the two first slits 111 to communicate with the two first slits 111 . The second slot 112 of the indented slot is parallel to the non-radiating side of the radiation patch 1040 , and the two first slots 111 of the indented slot are parallel to the radiating edge of the radiation patch 1040 . In this way, in the process of resonating the radiation patch 1040, since the center of the radiation patch 1040 is provided with slits on both sides opposite to the center, and the slits are arranged symmetrically with the center of the radiation patch 1040, a new resonance point is generated. The resonant point of 1042 matches the resonant point generated by the feeding of the first resonant cavity 1042 and the second resonant cavity 1044, effectively increasing the bandwidth of the single-layer broadband microstrip patch antenna 100, making the absolute bandwidth reach 180M, relative to the center frequency point The relative bandwidth reaches 7%. At the same time, the radiation patch 1040 can also improve the cross-polarization performance of the pattern.

The first resonant cavity 1042 is connected with the second resonant cavity 1044, and both the first resonant cavity 1042 and the second resonant cavity 1044 are parallel to the radiation side of the radiation patch 1040; the grounding short-circuit pin 1046 is arranged between the first resonant cavity 1042 and the connected first resonant cavity 1044. The middle of the second resonant cavity 1044 is short-circuited to connect the first resonant cavity 1042 to the metal ground; the microstrip transmission line 1048 is connected to the first resonant cavity 1042 and the second resonant cavity 1044 .

The above-mentioned first resonant cavity 1042 is connected to the second resonant cavity 1044, and both the first resonant cavity 1042 and the second resonant cavity 1044 are parallel to the radiation side of the radiation patch 1040, and are used to excite the radiation patch 1040 by means of edge coupling . The first resonant cavity 1042 and the second resonant cavity 1044 are arranged to be parallel to the radiation side of the radiating patch 1040, so that the overall area of the patch antenna 100 will not increase due to the provision of the first resonant cavity 1042 and the second resonant cavity 1044. Too large makes the structure of the patch antenna 100 compact. The ground short-circuit pin 1046 is arranged in the middle of the connected first resonant cavity 1042 and the second resonant cavity 1044, and is short-circuited to connect the first resonant cavity 1042 and the metal ground; the microstrip transmission line 1048 is connected to the first resonant cavity 1042 and the second resonant cavity 1044 connect. So designed, the microstrip transmission line 1048 is used to feed the first resonant cavity 1042 and the second resonant cavity 1044 . Using the feeding mode of the microstrip transmission line 1048 makes the feeding structure of the patch antenna 100 simpler, and provides convenience for the integrated feeding mode of the patch antenna 100 .

Referring to FIGS. 2-4 , in one embodiment, the radiation patch 1040 includes a single-slit radiation patch 10402 , a double-slit radiation patch 10404 or a multi-slit radiation patch 10406 .

Specifically, the two sides opposite to the center of the radiation patch 1040 of the single-layer broadband microstrip patch antenna 100 are provided with slits, and the slits are symmetrical with the center of the radiation patch 1040 . The slits of the radiation patch 1040 may be single slit, double slit or multiple slits. A single slit means that each side of the radiation patch 1040 includes a scallop-shaped slit, and the two scalloped slits on both sides are centrally symmetric with respect to the center of the radiation patch 1040 . Double slits means that each side of the radiation patch 1040 includes two indented slits, and the four indented slits on both sides are centrally symmetric with respect to the center of the radiation patch 1040 . Multiple slits means that each side of the radiation patch 1040 includes a plurality of indented slits (taking FIG. 4 as an example, each side includes three indented slits), and the plurality of indented slits on both sides of the radiation patch 1040 The center is centrosymmetric. The second slot 112 of the indented slot is parallel to the non-radiating side of the radiation patch 1040 , and the two first slots 111 of the indented slot are parallel to the radiating edge of the radiation patch 1040 . The matching degree of the radiation patches 1040 is increased due to the increase of the number of slits provided on the radiation patches 1040 .

In one of the embodiments, the opening directions of the chevron-shaped slits on the double-slit radiating patch 10404 or the multi-slit radiating patch 10406 are the same. Specifically, the same opening direction means that the opening directions of the indented openings formed by the slits are the same.

Specifically, the double-slit radiation patch 10404 or the multi-slit radiation patch 10406 and the radiation patch 1040 are provided with two or more indented slits, and the opening directions of the two or more indented slits are the same. The original surface current path is cut off based on the zigzag-shaped slit, and the current flows around the edge of the slit to make the path longer. When the opening directions of the indented slits on the double-slit radiating patch 10404 or the multi-slit radiating patch 10406 are the same, the direction in which the current flows around the edge of the slit is consistent, and the resonant frequency is adjusted to achieve multiple resonant frequencies. , thereby increasing the bandwidth. Further, the opening directions of the two or more groove-shaped slits are designed to be the same, which also facilitates the processing of the slits and simplifies the structure, thereby reducing the processing steps and the production cost.

In one of the embodiments, the width of the slit is 1.5mm˜3.0mm. Based on the relationship between the length of the radiating side, the length of the non-radiating side and the slot width of the radiating patch 1040 on the resonant frequency of the patch antenna 100, the slot width is set to 1.5mm˜3.0mm, so that the resonant frequency of the radiating patch 1040 is In the best case, a wide frequency band is obtained, and at the same time, the patch antenna 100 is better matched with the impedance line width of the single-layer dielectric substrate 102 .

In one of the embodiments, the first resonant cavity 1042 and the second resonant cavity 1044 are both a quarter resonant cavity or a half resonant cavity.

The above-mentioned first resonant cavity 1042 and second resonant cavity 1044 may be a quarter resonant cavity or a half resonant cavity. Either a quarter resonant cavity or a half resonant cavity can be arranged parallel to the radiation side of the radiation patch 1040 for coupling and feeding the radiation patch 1040 . The quarter resonant cavity or the half resonant cavity is arranged parallel to the radiation side of the radiating patch 1040 , so that the structure of the patch antenna 100 is compact, and the size of the patch antenna 100 is hardly increased compared with the conventional patch antenna 100 .

In one embodiment, the thickness of the single-layer dielectric substrate 102 is 2.5 mm˜3.5 mm; the dielectric constant of the single-layer dielectric substrate 102 is 2.0˜3.0; and the radius of the grounding shorting pin 1046 is 0.2 mm˜1.0 mm.

The thickness of the above-mentioned single-layer dielectric substrate 102 is 2.5 mm˜3.5 mm, and selecting a thicker single-layer dielectric substrate 102 can further increase the bandwidth. The dielectric constant of the single-layer dielectric substrate 102 is 2.0-3.0. Based on the different dielectric constants of the single-layer dielectric substrate 102, the resonant frequency of the patch antenna 100 will also change within a certain range. The single-layer dielectric substrate 102 can further increase the bandwidth. The radius of the grounding shorting pin 1046 is 0.2 mm˜1.0 mm, so that the radiation patch 1040 can better match the impedance line width of the single-layer dielectric substrate 102 .

In one embodiment, the length of the radiating side of the radiating patch 1040 is greater than the length of the non-radiating side, and the length of the radiating side of the radiating patch 1040 is greater than the sum of the lengths of the first resonant cavity 1042 and the second resonant cavity 1044 .

Specifically, the length of the radiating side of the radiating patch 1040 is greater than the length of the non-radiating side, and such design can reduce the impedance of the radiating patch 1040, thereby improving the matching degree of the patch antenna 100.

Specifically, the length of the radiating side of the radiation patch 1040 is greater than the sum of the lengths of the first resonant cavity 1042 and the second resonant cavity 1044. Such design is beneficial to further increase the bandwidth of the patch antenna 100. At the same time, the length of the radiating side is greater than The sum of the lengths of the first resonant cavity 1042 and the second resonant cavity 1044, and the first resonant cavity 1042 and the second resonant cavity 1044 are parallel to the radiation side of the radiation patch 1040, this design can also help reduce the size of the antenna unit 104 It is beneficial to the miniaturization development of the patch antenna 100 .

In one embodiment, the length of the non-radiating side of the radiating patch 1040 is half the wavelength of the medium.

Specifically, the radiation patch 1040 is rectangular, and the length of the radiating side is greater than the length of the non-radiating side. Preferably, the slits on both sides of the rectangular radiation patch 1040 are axisymmetric with the symmetry axis of the rectangular radiation patch 1040 as the symmetry axis. Based on the relationship between the length of the radiating side, the length of the non-radiating side and the slot width of the radiating patch 1040 on the resonant frequency of the patch antenna 100, the length of the non-radiating side of the radiating patch 1040 is half the medium wavelength, and the The slit width is set to 1.5mm to 3.0mm. In this way, the length of the radiating side, the length of the non-radiating side and the width of the slit of the radiation patch 1040 can be optimally matched, and the resonant frequency of the radiation patch 1040 can be optimized to obtain a wider frequency band. This design also enables the patch antenna 100 to better match the impedance line width of the single-layer dielectric substrate 102 . The length of the non-radiating side of the radiation patch 1040 is half the wavelength of the medium, and at the same time, the area of the radiation patch 1040 can be only the square of the half wavelength corresponding to the operating frequency, so that the patch antenna 100 can be applied to the size-constrained antenna. Production of Large Scale Array Patch Antenna 100.

In a specific embodiment of the present application, a single-layer broadband microstrip patch antenna 100 is provided, and its designed working frequency band is 2.5G-2.6G. The plate type of the single-layer dielectric substrate 102 is AD250, the dielectric constant of the dielectric substrate is preferably 2.5, the loss tangent of the dielectric substrate is 0.0013, and the thickness of the dielectric substrate is 3.175 mm. The radiation patch 1040 is preferably a rectangular double-slit radiation patch 1040, and without loss of generality, it can also be a rectangular single-slit or a rectangular multi-slit patch. The length of the non-radiating side of the double-slit radiation patch 10404 is 31 mm, the length of the radiating side is 36 mm, the width of the slit of the double-slit radiation patch 10404 is both 2.5 mm, and the first resonant cavity 1042 and the second resonant cavity 1044 are both selected as A quarter-wave resonator, the length of the quarter-wave resonator is 17.5mm, the width of the quarter-wave resonator is 2mm, the radius of the ground shorting pin 1046 is 0.5mm, and the width of the microstrip transmission line 1048 is 9 mm, corresponding to the 50-ohm impedance line width of the single-layer dielectric substrate 102 .

As shown in FIG. 6 , it is a simulation diagram of S11 parameters of the single-layer broadband microstrip patch antenna 100 according to the embodiment of the present application. Among them, the frequency bandwidth with S11 value not greater than -10dB is 2.48G-2.66G, the absolute bandwidth reaches 180M, and the relative bandwidth relative to the center frequency point reaches 7%, which is much higher than the ordinary single-layer microstrip patch antenna 100 about 1%- 2% relative bandwidth.

As shown in FIG. 7 , it is the azimuth plane gain pattern of the single-layer broadband microstrip patch antenna 100 at the frequency of 2.6G according to the embodiment of the application, the gain value reaches 7dB, and the single-layer broadband microstrip patch antenna 100 is normally cross-polarized. The ratio is greater than 47dB, and the cross-polarization ratio within the range of ±60° of the azimuth plane is greater than 20dB.

As shown in FIG. 8 , which is the elevation plane gain pattern of the single-layer broadband microstrip patch antenna 100 of the embodiment of the present application at a frequency of 2.6G, the cross-polarization ratio is greater than 30dB in the range of ±60° of the elevation plane.

In one embodiment, the single-layer broadband microstrip patch antenna 100 further includes a radio frequency connector 106 . The RF connector 106 is located on the backside of the single-layer dielectric substrate 102 and is connected to the microstrip transmission line 1048 via a coaxial probe.

Specifically, the single-layer broadband microstrip patch antenna 100 further includes a radio frequency connector 106 for feeding the first resonant cavity 1042 and the second resonant cavity 1044 through the microstrip transmission line 1048 . The RF connector 106 may be an SMA (Sub Miniature version A) connector. The radio frequency connector 106 may also choose any other form of connector. The radio frequency connector 106 is located on the back of the single-layer dielectric substrate 102 , and the radio frequency connector 106 is connected to the microstrip transmission line 1048 through a coaxial probe, so as to realize feeding. The connection method of the coaxial probe is beneficial to the patch antenna 100 Integrated with the RF circuit.

Specifically, the radio frequency connector 106 is located on the back of the single-layer dielectric substrate 102 , the radio frequency connector 106 is connected to the microstrip transmission line 1048 through a coaxial probe, and the microstrip transmission line 1048 is connected to the first resonant cavity 1042 and the second resonant cavity 1044 . The first resonant cavity 1042 is connected to the second resonant cavity 1044, and the ground short-circuit pin 1046 is disposed in the middle of the first resonant cavity 1042 and the second resonant cavity 1044, and short-circuits the first resonant cavity 1042 to the metal ground. In this way, the RF connector 106 feeds the first resonant cavity 1042 and the second resonant cavity 1044 through the microstrip transmission line 1048 . In addition, the first resonant cavity 1042 and the second resonant cavity 1044 are both parallel to the radiation side of the radiation patch 1040, and are used to excite the radiation patch 1040 by means of edge coupling. Using the feeding mode of the microstrip transmission line 1048 makes the feeding structure of the patch antenna 100 simpler, and provides convenience for the integrated feeding mode of the patch antenna 100 .

Specifically, the radio frequency connector 106 is connected to the microstrip transmission line 1048 through a coaxial probe, and the ground short-circuit pin 1046 then connects the first resonant cavity 1042 and the second resonant cavity 1044 to the microstrip transmission line 1048. The microstrip transmission line 1048 uses In order to feed the first resonant cavity 1042 and the second resonant cavity 1044, the first resonant cavity 1042 and the second resonant cavity 1044 excite the radiation patch 1040 through edge coupling. During the resonance process of the radiation patch 1040, a new resonance point is generated because the center of the radiation patch 1040 is provided with slits on opposite sides, and the slits are arranged symmetrically with the center of the radiation patch 1040. The first resonant cavity 1042 and the resonant point generated by the second resonant cavity 1044 are matched to effectively increase the bandwidth of the single-layer broadband microstrip patch antenna 100, so that the absolute bandwidth reaches 180M, and the relative bandwidth relative to the center frequency point reaches 100M. 7%. At the same time, the radiation patch 1040 can also improve the cross-polarization performance of the pattern.

In one embodiment, as shown in FIG. 5 , the radiation patch 1040 is further provided with a rectangular patch 1050 , one end of the rectangular patch is connected to a radiation edge of the radiation patch 1040 , and the other end penetrates the radiation patch 1040 It is connected with the other radiating side of the radiating patch 1040 ; the gap is located on the opposite sides of the rectangular patch 1050 . Preferably, the center of the rectangular patch 1050 coincides with the axis of symmetry of the radial patch 1040, in other words, the center of the rectangular patch 1050 coincides with the center of the radial patch 1040.

Specifically, two opposite sides of the center of the radiation patch 1040 are provided with slits, and the slits are symmetrical with the center of the radiation patch 1040 , the slits include a slot-shaped slot, and each slot-shaped slot includes two opposite first slots 111 and The ends on the same side of the two first slits 111 are connected to communicate with the second slits 112 of the two first slits 111 . The second slot 112 of the indented slot is parallel to the non-radiating side of the radiation patch 1040 , and the two first slots 111 of the indented slot are parallel to the radiating edge of the radiation patch 1040 . The slits of the radiation patch 1040 include a single-slit radiation patch 10402 , a double-slit radiation patch 10404 and a multi-slit radiation patch 10406 .

Specifically, the slit of the single-slit radiation patch 10402 is formed by etching a rectangular slit, and then disposing a rectangular patch 1050 in the radiation patch 1040 with a rectangular slit. Preferably, the radiation patch 1040 is a rectangle, and the symmetry axis of the rectangle formed by the rectangular slit, the symmetry axis of the radiation patch 1040 and the symmetry axis of the rectangular patch 1050 are coincident. In other words, the center of the rectangle formed by the rectangular slit, the center of the radiation patch 1040 , and the center of the rectangular patch 1050 coincide. One end of the rectangular patch 1050 is connected with a radiating side of the radiation patch 1040, and the other end penetrates the radiation patch 1040 and is connected with the other radiating side of the radiation patch 1040, thus forming a zigzag gap, and the zigzag gap is The center of the radiation patch 1040 is center-symmetric.

Further, the formation manner of the slits of the double-slit radiation patch 10404 or the multi-slit radiation patch 10406 is similar to that of the single-slit radiation patch 10402 . The slits of the double-slit radiation patch 10404 or the multi-slit radiation patch 10406 are formed in the following manner. After etching two or more rectangular slits, a rectangular patch 1050 is placed in the radiation patch 1040 with two or more rectangular slits. Preferably, the symmetry axes of the multiple rectangles formed by the multiple rectangular slits are coincident. . One end of the rectangular patch 1050 is connected to a radiating edge of the radiation patch 1040, and the other end penetrates the radiation patch 1040 and is connected to the other radiating edge of the radiation patch 1040, thus forming an indented double slot or multiple slots, The opening directions of the two or more indented slits are the same, and are centrally symmetric about the center of the radiation patch 1040 . In this way, the structure of the radiation patch 1040 is simple and the manufacturing cost is lower.

The technical features of the above embodiments can be combined arbitrarily. In order to make the description simple, all possible combinations of the technical features in the above embodiments are not described. However, as long as there is no contradiction in the combination of these technical features It is considered to be the range described in this specification.

The above examples only represent several embodiments of the present application, and the descriptions thereof are relatively specific and detailed, but should not be construed as a limitation on the scope of the invention patent. It should be pointed out that for those skilled in the art, without departing from the concept of the present application, several modifications and improvements can be made, which all belong to the protection scope of the present application. Therefore, the scope of protection of the patent of the present application shall be subject to the appended claims.

Claims

A single-layer broadband microstrip patch antenna, comprising: a single-layer dielectric substrate and an antenna unit; the front and back of the single-layer dielectric substrate are covered with a metal layer, and the metal layer on the back of the single-layer dielectric substrate is a metal ground; the metal layer on the front side of the single-layer dielectric substrate is etched to form an antenna unit, the antenna unit includes a radiation patch, a first resonant cavity, a second resonant cavity, a ground short-circuit pin and a microstrip Transmission line;

There are slits on opposite sides of the center of the radiation patch, the slits are centrally symmetric with the center of the radiation patch, the slits include a slot-shaped slot, and each slot-shaped slot includes two opposite The first slit and the end of the same side connecting the two first slits are connected to the second slit of the two first slits, and the second slit of the indented slit is parallel to the non-radiating side of the radiation patch, so The two first slits of the indented slit are parallel to the radiation edge of the radiation patch;

the first resonant cavity is connected to the second resonant cavity;

The ground short-circuit pin is arranged in the middle of the connected first resonant cavity and the second resonant cavity, and short-circuits the first resonant cavity and the metal ground;

The microstrip transmission line is connected to the first resonant cavity and the second resonant cavity.
The single-layer broadband microstrip patch antenna according to claim 1, wherein the metal layer is a copper clad layer.
The single-layer broadband microstrip patch antenna of claim 2, wherein the radiating patch comprises a single-slit radiating patch, a double-slit radiating patch, or a multi-slit radiating patch.
The single-layer broadband microstrip patch antenna according to claim 2, wherein the first resonant cavity and the second resonant cavity are both parallel to the radiation side of the radiation patch.
The single-layer broadband microstrip patch antenna according to claim 2, wherein the length of the two first slots of each zigzag slot is the same, and the length of each first slot in the two first slots is smaller than that of the second slot. The length of the gap.
The single-layer broadband microstrip patch antenna according to claim 3, wherein the opening directions of the groove-shaped slits on the double-slit radiation patch or the multi-slit radiation patch are the same.
The single-layer broadband microstrip patch antenna according to claim 2, wherein the width of the slot is 1.5mm˜3.0mm.
The single-layer broadband microstrip patch antenna according to claim 2, wherein the first resonant cavity and the second resonant cavity are both a quarter resonant cavity or a half resonant cavity.
The single-layer broadband microstrip patch antenna according to claim 2, wherein the thickness of the single-layer dielectric substrate is 2.5mm-3.5mm; the dielectric constant of the single-layer dielectric substrate is 2.0-3.0; the The radius of the ground short-circuit pin is 0.2mm to 1.0mm.
The single-layer broadband microstrip patch antenna according to claim 2, wherein the radiating patch is rectangular, and the slot is axisymmetric with an axis of symmetry of the radiating patch as the axis of symmetry.
The single-layer broadband microstrip patch antenna according to claim 10, wherein the length of the radiating side of the radiating patch is greater than the length of the non-radiating side, and the length of the radiating side of the radiating patch is greater than that of the non-radiating side. The length is greater than the sum of the lengths of the first resonant cavity and the second resonant cavity.
The single-layer broadband microstrip patch antenna of claim 10, wherein the length of the non-radiating side of the radiating patch is half a medium wavelength.
The single-layer broadband microstrip patch antenna according to claim 2, wherein the single-layer broadband microstrip patch antenna further comprises a radio frequency connector, the radio frequency connector is located on the back of the single-layer dielectric substrate, and The microstrip transmission line is connected via a coaxial probe.
The single-layer broadband microstrip patch antenna of claim 13, wherein the radio frequency connector is used to feed the first resonant cavity and the second resonant cavity through the microstrip transmission line.
The single-layer broadband microstrip patch antenna according to any one of claims 1 to 14, wherein a rectangular patch is further arranged in the radiation patch, and one end of the rectangular patch is connected to the radiating patch. One of the radiating edges is connected, and the other end penetrates the radiating patch and is connected with the other radiating edge of the radiating patch; the slits are located on opposite sides of the rectangular patch.
The single-layer broadband microstrip patch antenna according to claim 15, wherein the radiating patch is a single-slit radiating patch, and the single-slit radiating patch is etched with a rectangular slit and then has a The rectangular slot is formed by arranging a rectangular patch in the radiation patch.
The single-layer broadband microstrip patch antenna according to claim 16, wherein the radiating patch is a double-slit radiating patch or a multi-slit radiating patch, and the The slit is formed by arranging a rectangular patch in the radiation patch with two or more rectangular slits after etching two or more rectangular slits.
A method of forming a single-layer broadband microstrip patch antenna, comprising:

A single-layer dielectric substrate is provided, the front and back of the single-layer dielectric substrate are covered with metal layers, and the metal layer on the back of the single-layer dielectric substrate is a metal ground;

etching the metal layer on the front surface of the single-layer dielectric substrate to form an antenna unit, the antenna unit includes a radiation patch, a first resonant cavity, a second resonant cavity, a ground shorting pin and a microstrip transmission line;

etching rectangular slits in the radiation patch;

A rectangular patch is arranged in the radiation patch with the rectangular slot, one end of the rectangular patch is connected to one of the radiation edges of the radiation patch, and the other end penetrates the radiation patch and is connected to the radiation patch. connected with the other said radiation edge of the radiation patch; the symmetry axis of the rectangle formed by the rectangular slit, the symmetry axis of the radiation patch and the symmetry axis of the rectangular patch coincide;

Wherein, the first resonant cavity is connected to the second resonant cavity; the ground short-circuit pin is arranged in the middle of the connected first resonant cavity and the second resonant cavity, and short-circuits the first resonator The cavity is connected to the metal ground; the microstrip transmission line is connected to the first resonant cavity and the second resonant cavity.
19. The method of claim 18, wherein etching rectangular slits in the radiation patch comprises: etching a plurality of rectangular slits in the radiation patch, a plurality of rectangular slits formed by the plurality of rectangular slits The axes of symmetry coincide.