Wide beam antenna suitable for millimeter wave phased array and its design method

Abstract

The present invention relates to the field of wireless communication technology, and is a wide beam antenna suitable for millimeter wave phased array and a design method thereof. The wide beam antenna comprises an integrated substrate gap waveguide structure and a radiation structure; the integrated substrate gap waveguide structure comprises a bottom metal plate, a first dielectric substrate, a second dielectric substrate, a third dielectric substrate and a top metal plate, the bottom metal plate is printed on the lower surface of the first dielectric substrate, and the top metal plate is printed on the upper surface of the third dielectric substrate; the radiation structure comprises an electromagnetic radiation window and an open resonant ring; an electromagnetic radiation window is etched on the top metal plate, and an open resonant ring is arranged in the electromagnetic radiation window; an annular gap is formed between the electromagnetic radiation window and the open resonant ring; a plurality of electromagnetic bandgap structures are embedded in the third dielectric substrate, and the open resonant ring and the lower surface of the third dielectric substrate are connected by the electromagnetic bandgap structure. The present invention has the advantages of high integration, low-cost batch manufacturing, flat beam jump and large coverage.

Description

Technical Field

[0001] The present invention relates to the field of wireless communication technology, and in particular to a wide-beam antenna suitable for a millimeter-wave phased array and a design method thereof. Background Art

[0002] With the development of wireless communication technology, the industrial scale of 5G communication is growing, and its mobile terminal line is developing in the direction of miniaturization, integration, scannability and large coverage. Phased array antennas can use beamforming networks to simultaneously realize multiple independent high-gain beams. They have the advantages of high flexibility, wide scanning angle, and high reliability. They can not only achieve wide-area coverage and broadband transmission, but also meet urgent needs such as random access and multi-point communication. At present, under the main driving force of the low-altitude economy, highly integrated miniaturized phased array antennas will play an important role in drones, highway detection and scanning base stations. Realizing wide-beam antennas is an important prerequisite and method for realizing wide-scan phased array antennas.

[0003] Integrated Substrate Gap Waveguide (ISGW) is widely used in RF front-end devices such as antennas, filters, and couplers due to its advantages of high integration, light weight, low cost, low radiation loss and mode conversion loss. However, current research shows that there is no literature report on the design of high-performance phased array antenna units based on integrated substrate gap waveguides. Summary of the invention

[0004] In order to solve the problems that existing phased array units are difficult to integrate, have small coverage and small bandwidth, the present invention provides a wide-beam antenna suitable for millimeter-wave phased arrays and a design method thereof, which has the technical effects of high integration, broadband and wide coverage, and can be applied to highly integrated phased array antennas in microwave millimeter, millimeter wave and terahertz frequency bands.

[0005] On the one hand, an embodiment of the present invention provides a wide beam antenna suitable for a millimeter wave phased array, comprising an integrated substrate gap waveguide structure and a radiation structure;

[0006] The integrated substrate gap waveguide structure comprises a bottom metal plate, a first dielectric substrate, a second dielectric substrate, a third dielectric substrate and a top metal plate which are stacked from bottom to top, the bottom metal plate is printed on the lower surface of the first dielectric substrate, and the top metal plate is printed on the upper surface of the third dielectric substrate;

[0007] The radiation structure includes an electromagnetic radiation window and an open resonant ring; the electromagnetic radiation window is etched on the top metal plate, and at least two open resonant rings are arranged in the electromagnetic radiation window; a ring gap is formed between the electromagnetic radiation window and the open resonant ring;

[0008] A plurality of electromagnetic band gap structures are embedded in the third dielectric substrate, and the plurality of electromagnetic band gap structures are regularly arranged in the peripheral area of ​​the open resonant ring; the open resonant ring and the lower surface of the third dielectric substrate are connected through the electromagnetic band gap structure.

[0009] Preferably, the openings of the two open resonant rings are arranged opposite to each other, so that a pair of rectangular gaps are formed between the two resonant rings.

[0010] Preferably, a plurality of regularly arranged electromagnetic band gap structures surround the open resonant ring to form a dielectric resonator-like antenna.

[0011] Preferably, the electromagnetic bandgap structure comprises a metal via and a metal sheet printed on the lower surface of the third dielectric substrate, and the metal via is connected from the metal sheet to the top metal plate on the upper surface of the third dielectric substrate;

[0012] The open resonant ring and the lower surface of the third dielectric substrate are connected through a metal via.

[0013] Preferably, the wide beam antenna further comprises a step-type microstrip line feeder printed on the upper surface of the second dielectric substrate. Further, the step-type microstrip line feeder comprises a first microstrip line and a second microstrip line with impedance matching, and the first microstrip line and the second microstrip line have different widths.

[0014] On the other hand, an embodiment of the present invention further provides a method for designing the above-mentioned wide beam antenna suitable for a millimeter wave phased array, comprising the following steps:

[0015] Adjust the size of the open resonant ring and the annular gap;

[0016] Adjust the size of the electromagnetic radiation window and the feeding position;

[0017] Adjust the cell size of the electromagnetic bandgap structure.

[0018] Compared with the prior art, the beneficial effects of the present invention include:

[0019] 1. The wide-beam antenna suitable for millimeter-wave phased array provided by the present invention mainly includes an integrated substrate gap waveguide structure and a radiation cavity (i.e., a radiation structure), wherein the integrated substrate gap waveguide structure is a highly integrated electromagnetic metamaterial, and the waveguide structure and the radiation cavity adopt an integrated design scheme, which further improves the integration of the antenna.

[0020] 2. In the present invention, the integrated substrate gap waveguide structure adopts a full PCB process, which is mainly realized by stacking and printing three layers of dielectric substrates. The waveguide structure simultaneously realizes the functions of suppressing surface waves and in-phase reflection characteristics, which will suppress the floor edge effect of the antenna, so that the beam width of the antenna is widened to a certain extent. In addition, the in-phase reflection characteristics enable the antenna to maintain the advantage of a low profile.

[0021] 3. In the present invention, the radiation structure mainly includes an antenna similar to a dielectric resonator (i.e., a dielectric resonant cavity), in which two open resonant rings are embedded in the dielectric resonator to obtain additional resonant frequencies, so that the working frequency band of the antenna is broadened and the beam width is expanded at the same time. Compared with traditional dielectric resonator antennas and dipole antennas, etc., this antenna benefits from the integrated design of the feeding structure and the radiation structure, and its profile height is lower, which is easier to integrate and facilitates the formation of a larger-scale phased array antenna. Compared with traditional phased array antenna units, the present invention has the advantages of high integration, low-cost mass production, flat beam jump and large coverage. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] Figure 1 This is a structural diagram of a wide beam antenna suitable for a millimeter wave phased array provided by an embodiment of the present invention;

[0023] Figure 2 It is a defect terrain-integrated substrate gap waveguide structure diagram of a wide beam antenna suitable for a millimeter wave phased array provided in an embodiment of the present invention;

[0024] Figure 3 1 is an S parameter curve diagram of an integrated substrate gap waveguide for a wide beam antenna of a millimeter wave phased array provided in an embodiment of the present invention, wherein sub-graphs (a) and (b) are respectively a reflection coefficient curve and a reflection phase curve;

[0025] Figure 4 is an S parameter curve diagram of a wide beam antenna applicable to a millimeter wave phased array provided in an embodiment of the present invention;

[0026] Figure 5 is an input impedance curve diagram of a wide beam antenna applicable to a millimeter wave phased array provided in an embodiment of the present invention;

[0027] Figure 6 Schematic diagram of the electric field distribution of a wide beam antenna suitable for a millimeter wave phased array at two resonance points provided by an embodiment of the present invention, wherein (a) is a schematic diagram of the electric field distribution at resonance point two at 30.4 GHz, and (b) is a schematic diagram of the electric field distribution at resonance point one at 28.5 GHz;

[0028] Figure 7 It is the H-plane radiation pattern (rectangular coordinate system) of the wide beam antenna applicable to the millimeter wave phased array provided by the embodiment of the present invention at 28, 28.5 and 29 GHz;

[0029] Figure 8 It is the H-plane radiation pattern (polar coordinate system) of the wide beam antenna applicable to the millimeter wave phased array provided by the embodiment of the present invention at 28, 28.5 and 29 GHz;

[0030] Fig. 9 It is a schematic diagram of parameter research and analysis of a wide beam antenna suitable for a millimeter wave phased array provided in an embodiment of the present invention, wherein (a), (b) and (c) are respectively schematic diagrams of the influence of the inner side length of an open resonant ring on the S parameters, a schematic diagram of the influence of the distance between a pair of open resonant rings on the S parameters, and a schematic diagram of the influence of the radius of a metal via on the S parameters.

[0031] Reference numerals:

[0032] II-radiation structure; I-feeding structure; 1-bottom metal plate; 2-first dielectric substrate; 3-second dielectric substrate; 4-step-type microstrip feeder; 5-electromagnetic bandgap structure; 6-top metal plate; 7-open resonant ring; 8-rectangular gap; 9-third dielectric substrate; 10-annular gap; 11-electromagnetic radiation window; 12-metal disc; 13-metal via. DETAILED DESCRIPTION

[0033] The present invention provides a wide-beam antenna suitable for millimeter-wave phased arrays and a design method thereof, so as to solve the problems that existing phased array units are difficult to integrate, have a small coverage range and a small bandwidth, while achieving the technical effects of high integration, broadband and wide coverage, and applying highly integrated phased array antennas in microwave millimeter, millimeter wave and terahertz frequency bands.

[0034] In order to make the above-mentioned purposes, features and advantages of the present invention more obvious and easy to understand, the following specifically illustrates the implementation mode of the present invention in conjunction with the accompanying drawings and examples. The examples are given only for illustrative purposes and cannot be understood as limiting the present invention. The accompanying drawings are only for reference and illustration purposes and do not constitute a limitation on the scope of patent protection of the present invention. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0035] like Figure 1 , which is a structural diagram of a wide beam antenna of a millimeter wave phased array provided in an embodiment of the present invention. In an embodiment of the present invention, the antenna includes a radiation structure II and a feeding structure I stacked in sequence from top to bottom, and the feeding structure (i.e., feeding layer) and the radiation structure (i.e., radiation layer) are designed in an integrated manner. Among them, the radiation structure II is located above the feeding structure I, and the feeding structure is a step-type microstrip line feeder 4, which is used to achieve better impedance matching characteristics and obtain better notch performance.

[0036] The wide beam antenna of this embodiment is designed based on a three-layer integrated substrate gap waveguide (I and II together constitute a waveguide). The waveguide mainly includes three layers of dielectric substrates and two layers of metal plates, specifically including a bottom metal plate 1, a first dielectric substrate 2, a second dielectric substrate 3, a third dielectric substrate 9 and a top metal plate 6 stacked from bottom to top, the bottom metal plate is printed on the lower surface of the first dielectric substrate 2, and the top metal plate is printed on the upper surface of the third dielectric substrate 9.

[0037] The radiation structure includes an electromagnetic radiation window and an open resonant ring. An electromagnetic radiation window 11 is etched on the top metal plate on the upper surface of the third dielectric substrate 9, and at least two open resonant rings 7 are arranged in the electromagnetic radiation window. The openings of the two open resonant rings are arranged oppositely, so that a pair of rectangular gaps 8 are formed between the two resonant rings. The rectangular gap is used to adjust the input impedance of the antenna, that is, to adjust the frequency response characteristics; and an annular gap 10 is formed between the electromagnetic radiation window 11 and the open resonant ring 7, and the annular gap is used to adjust the impedance matching. A plurality of electromagnetic bandgap structures 5 are embedded in the third dielectric substrate 9. The plurality of electromagnetic bandgap structures 5 are regularly arranged in the outer area of ​​the open resonant ring 7. The plurality of regularly arranged electromagnetic bandgap structures surround the open resonant ring to form a dielectric resonator-like antenna; from another perspective, it is equivalent to that in the array structure formed by the regular arrangement of a plurality of electromagnetic bandgap structures, m*n electromagnetic bandgap structures are removed to form a vacant area, and the vacant area is located in the electromagnetic radiation window. In this embodiment, 5*5 electromagnetic bandgap structures in the middle part are removed.

[0038] The width of the rectangular gap 8 is △L1; after the two open resonant rings 7 form a pair of open resonant rings, the length of the inner hollow rectangular area is L and the width is W. Figure 1 shown.

[0039] In this embodiment, the electromagnetic radiation window is a square, and the radiation window ensures that the main radiation direction of the antenna is perpendicular to the antenna plane (XOY plane). The resonant frequency of the antenna can be tuned by adjusting the window side length of the electromagnetic radiation window. The open resonant ring is used to excite additional resonant frequency points, which are fully symmetrical about the X-axis and Y-axis planes and do not interfere with the original resonant mode, thereby expanding the working bandwidth.

[0040] Each electromagnetic bandgap structure 5 includes a metal via 13 and a metal sheet printed on the lower surface of the third dielectric substrate, and the metal via is connected from the metal sheet to the top metal plate on the upper surface of the third dielectric substrate. The metal sheet can be a metal disc 12, the metal via is a cylinder, and each metal disc and the metal via are arranged concentrically to form a mushroom-shaped electromagnetic bandgap structure. The open resonant ring and the lower surface of the third dielectric substrate are connected through the metal via 13, so as to achieve antenna impedance matching and achieve good trapping performance.

[0041] In this embodiment, the electromagnetic radiation window 11 generates two main modes of the dielectric resonator antenna; in order to further increase the working bandwidth of the antenna, this embodiment introduces two open resonant rings 7 that are symmetrical about the X-axis and the Y-axis respectively. The open resonant ring adjusts the coupling between the intracavity modes, and when the coupling value is adjusted to a certain value, the maximum working bandwidth can be generated. Therefore, after adding the open resonant ring 7, the two main modes of the antenna evolve into main modes similar to those of the dielectric resonator antenna (but with a larger working bandwidth). In order to facilitate the distinction from the main modes of the traditional dielectric resonator antenna, it is called an electromagnetic metamaterial dielectric resonator antenna. The main radiation modes of the electromagnetic metamaterial dielectric resonator antenna are two modes jointly excited by the electromagnetic metamaterial dielectric resonator antenna and the open resonant ring.

[0042] Furthermore, the step-type microstrip line feeder 4 of this embodiment is printed on the upper surface of the second dielectric substrate of the integrated substrate gap waveguide, which is easy to impedance match. The input port impedance of the step-type microstrip line feeder 4 is 50 ohms. In order to increase the trapping capability of the antenna, the feeder of this embodiment is designed to include a first microstrip line 4-1 and a second microstrip line 4-2 with impedance matching. The widths of the two microstrip lines are different. By reasonably adjusting the line widths of the first microstrip line 4-1 and the second microstrip line 4-2, the impedance matching of the antenna can be controlled.

[0043] The integrated substrate gap waveguide based on the electromagnetic bandgap structural unit effectively suppresses the propagation of surface waves due to the existence of the electromagnetic bandgap. This characteristic will suppress the coupling of the phased array antenna unit. In addition, due to the in-phase reflection characteristics, the distance between the radiator and the reflecting floor of the antenna is no longer limited to a quarter of a wavelength, so it has a low profile characteristic.

[0044] Figure 3 The S parameter curve of the integrated substrate gap waveguide of the wide beam antenna of the millimeter wave phased array provided by the present invention, wherein (a) is the reflection coefficient curve and (b) is the reflection phase curve. The S parameter curve shows that in the 22.04-34GHz frequency band, the insertion loss is about 0.2dB, and the waveguide suppresses the propagation of surface waves. This characteristic can suppress the coupling problem between the traditional phased array antenna units. In addition, in the 18.5-

[0045] The 28GHz frequency band exhibits an in-phase reflection characteristic, that is, the incident wave and the reflected wave are superimposed in phase within this frequency band. Therefore, there is no quarter-wavelength limitation between the traditional antenna reflector and the radiator, which means that a lower profile can be achieved.

[0046] Figure 4The S parameters and gain curves of the wide beam antenna of the millimeter wave phased array provided by the present invention. From the S parameter curve, it can be concluded that the working bandwidth of the present invention is: 27.8-31.8GHz, the frequencies of the first and second resonance points are 28.5GHz and 30.4GHz respectively, and the antenna provided by the present invention excites two resonance points in the working frequency band. These two resonance points are jointly excited by the dielectric resonant cavity and the open resonant ring in the electromagnetic radiation window. This conclusion can be obtained from Figure 6 The electric field distribution of the two resonance points of the antenna is verified. In addition, thanks to the in-phase reflection characteristics of the integrated substrate gap waveguide, the antenna has an in-band peak gain of up to 7.2dBi while ensuring a wide beam.

[0047] Figure 5 The input impedance curve of the wide beam antenna of the millimeter wave phased array provided by the present invention. From the input impedance curve, it can be seen that the frequencies of the two resonance points of the excitation are 28.5GHz and 30.4GHz respectively, and in the range of 27.8-31.8GHz, the real part (Re) of the input impedance of the antenna is maintained at around 50 ohms, so the antenna exhibits good notch characteristics within the frequency band.

[0048] Figure 6 It is the electric field distribution of the wide beam antenna of the millimeter wave phased array provided by the present invention at two resonance points (resonance point 2 30.4GHz and resonance point 1 28.5GHz); From the electric field distribution diagram, it can be concluded that the electric field energy of the antenna at the two resonance points is mainly concentrated at the center thereof, especially the electric field distribution on the H plane (YOZ plane) is symmetrical, so a symmetrical radiation pattern is obtained on the H plane, from Figure 7 and Figure 8 It can be seen.

[0049] Figure 7 It is the H-plane radiation pattern (rectangular coordinate system) of the wide-beam antenna of the millimeter-wave phased array provided by the present invention at 28, 28.5 and 29 GHz; as can be seen from the figure, the H-plane beam width of the antenna is ±71°, and the beam jump is only about 1 dB. Compared with the traditional phased array antenna unit, it has the advantages of wide-bandwidth beam scanning and smaller beam jump; and it shows a consistent radiation pattern at different frequencies, showing good radiation characteristics.

[0050] Figure 8 is the H-plane radiation pattern (polar coordinate system) of the wide beam antenna of the millimeter wave phased array provided by the present invention at 28, 28.5 and 29 GHz; Figure 8 It shows that the radiation pattern (H plane) of the antenna maintains good consistency at different frequency points and has excellent symmetry, which is one of the advantages of the antenna.

[0051] Fig. 9This is a parameter study and analysis of the wide beam antenna of the millimeter wave phased array provided by the present invention, wherein sub-figure (a) illustrates the influence of the inner side length of the open resonant ring on the S parameter, (b) illustrates the influence of the distance between a pair of open resonant rings on the S parameter, and (c) illustrates the influence of the radius of the metal via on the S parameter. The figure shows that the resonant frequency, working bandwidth and matching characteristics of the antenna can be controlled by the size of the electromagnetic radiation window and the size of the integrated substrate gap waveguide, showing the characteristics of statically adjustable working bandwidth.

[0052] Compared with the existing phased array antenna units, the millimeter wave phased array wide beam antenna provided by the present invention has the following advantages:

[0053] (1) Wider beam width and larger communication coverage;

[0054] (2) The beam jumps at different frequencies are smaller;

[0055] (3) Direction of different frequencies on the H plane Figure 1 Excellent consistency;

[0056] (4) Larger working bandwidth and higher data transmission rate;

[0057] (5) The integrated substrate gap waveguide unit not only suppresses the mutual coupling between the phased array antenna units, but also enables the antenna to obtain a lower profile;

[0058] (6) The integrated design of the feed network and the radiation structure has lower losses in the millimeter wave frequency band, making it more suitable for applications with high power consumption requirements such as drones, base stations and satellites;

[0059] (7) It is a fully planar dielectric integrated structure with high integration, light weight and low cost.

[0060] Correspondingly, based on the same inventive concept, an embodiment of the present invention further provides a design method for a wide beam antenna suitable for a millimeter wave phased array. The design method comprises:

[0061] By adjusting the sizes of the split resonant ring, the rectangular gap, and the annular gap, the coupling between the split resonant ring and the dielectric resonator-like antenna embedded in the gap waveguide of the integrated substrate can be reasonably adjusted, and the quality factor of the antenna can be reduced, thereby widening its working bandwidth;

[0062] Adjusting the size of the electromagnetic radiation window, the feeding position and the size of the feeding microstrip line to control the beam width and beam jump of the wide bandwidth beam antenna;

[0063] The unit size of the electromagnetic bandgap structure is adjusted to control the input impedance of the wide bandwidth beam antenna, and the notch characteristic of the antenna can be tuned according to the input impedance.

[0064] A wide beam antenna suitable for a millimeter wave phased array and a design method thereof provided in an embodiment of the present invention, wherein the wide beam antenna mainly includes a highly integrated electromagnetic metamaterial-an integrated substrate gap waveguide structure and a radiation cavity, wherein the waveguide structure and the radiation cavity adopt an integrated design scheme, further improving the integration of the antenna. The integrated substrate gap waveguide structure adopts a full PCB process, which is mainly realized by stacking and printing three layers of dielectric substrates. The waveguide structure simultaneously realizes the suppression of surface waves and the in-phase reflection function, which will suppress the floor edge effect of the antenna, so that the beam width of the antenna is widened to a certain extent. In addition, the in-phase reflection characteristic enables the antenna to maintain the advantage of a low profile. Its radiation structure is composed of an antenna similar to a dielectric resonator, in which two open resonant rings are embedded in the dielectric resonator, thereby obtaining additional resonant frequencies, so that the working frequency band of the antenna is widened and the beam width is expanded at the same time. Compared with traditional dielectric resonator antennas and dipole antennas, the antenna benefits from the integrated design scheme of the feeding structure and the radiation structure, and its profile height is lower and easier to integrate. More importantly, it has a smaller beam jump (about 1dB) and coverage. Compared with the traditional phased array antenna unit, the present invention has the advantages of high integration, low-cost batch manufacturing, flat beam jump and large coverage.

[0065] The above-mentioned embodiments only express several preferred implementation modes of the present invention, and the description thereof is relatively specific and detailed, but it cannot be understood as limiting the scope of the invention patent. It should be pointed out that, for ordinary technicians in this technical field, several improvements and substitutions can be made without departing from the technical principle of the present invention, and these improvements and substitutions should also be regarded as the protection scope of the present invention. Therefore, the protection scope of the patent of the present invention shall be based on the protection scope of the claims.

Claims

1. A wide beam antenna suitable for a millimeter wave phased array, characterized in that: The wide beam antenna comprises an integrated substrate gap waveguide structure and a radiating structure; The integrated substrate gap waveguide structure comprises a bottom metal plate, a first dielectric substrate, a second dielectric substrate, a third dielectric substrate and a top metal plate which are stacked from bottom to top, the bottom metal plate is printed on the lower surface of the first dielectric substrate, and the top metal plate is printed on the upper surface of the third dielectric substrate; The radiation structure includes an electromagnetic radiation window and an open resonant ring; Etching an electromagnetic radiation window on the top metal plate, and arranging at least two open resonant rings in the electromagnetic radiation window; An annular gap is formed between the electromagnetic radiation window and the open resonant ring; A plurality of electromagnetic band gap structures are embedded in the third dielectric substrate, and the plurality of electromagnetic band gap structures are regularly arranged in the peripheral area of ​​the open resonant ring; The open resonant ring and the lower surface of the third dielectric substrate are connected via an electromagnetic band gap structure; The openings of the two open resonant rings are arranged opposite to each other, so that a pair of rectangular gaps are formed between the two resonant rings.

2. The wide beam antenna according to claim 1, characterized in that: A plurality of regularly arranged electromagnetic band gap structures surround the open resonant ring to form a dielectric resonator-like antenna.

3. The wide beam antenna according to claim 1, characterized in that: The electromagnetic bandgap structure includes a metal via and a metal sheet printed on the lower surface of the third dielectric substrate, and the metal via is connected from the metal sheet to the top metal plate on the upper surface of the third dielectric substrate; The open resonant ring and the lower surface of the third dielectric substrate are connected through a metal via.

4. The wide beam antenna according to claim 3, characterized in that: The metal sheet is a metal disc, the metal via is a cylinder, and the metal disc and the metal via are arranged concentrically to form a mushroom-shaped electromagnetic band gap structure.

5. The wide beam antenna according to claim 1, characterized in that: The wide beam antenna further comprises a step-type microstrip line feeder printed on the upper surface of the second dielectric substrate.

6. The wide beam antenna according to claim 5, characterized in that: The step-type microstrip line feed line comprises a first microstrip line and a second microstrip line with impedance matching, and the first microstrip line and the second microstrip line have different widths.

7. The wide beam antenna according to claim 1, characterized in that: A plurality of electromagnetic band gap structures are regularly arranged to form an array structure, and m*n electromagnetic band gap structures in the array structure are removed to form a vacant area, and the vacant area is located in the electromagnetic radiation window.

8. A method for designing a wide beam antenna according to claim 1, characterized in that: The following steps are involved: Adjust the size of the open resonant ring and the annular gap; Adjust the size of the electromagnetic radiation window and the feeding position; Adjust the cell size of the electromagnetic bandgap structure.

9. The design method according to claim 8, characterized in that: The wide beam antenna further comprises a step-type microstrip line feeder printed on the upper surface of the second dielectric substrate, wherein the step-type microstrip line feeder comprises a first microstrip line and a second microstrip line with impedance matching; The widths of the first microstrip line and the second microstrip line are adjusted.

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