A gear-type slot BTISGW leaky-wave antenna array

Abstract

The present invention discloses a gear-type slot BTISGW leaky wave antenna array, comprising an electromagnetic bandgap structure array, an antenna transmitting structure is arranged above the electromagnetic bandgap structure array; the antenna transmitting structure comprises an upper dielectric plate, a curved terminal load is arranged on the lower surface of the upper dielectric plate, and a first copper-clad layer is arranged on the upper surface of the upper dielectric plate; a plurality of slot units are opened on the first copper-clad layer, and the slot units are used to radiate electromagnetic waves out of space. The curved terminal load is used to absorb excess electromagnetic energy. By setting up this device, the size of the antenna can be greatly reduced, the electromagnetic shielding performance can be improved, and the antenna efficiency can be improved; the bandwidth of the antenna can be increased to realize spatial beam scanning in the forward quadrant; by setting a curved terminal load to absorb a small amount of reflected energy, the gain and radiation efficiency can be improved.

Description

Technical Field

[0001] The invention relates to the field of wireless communication antennas, and in particular to a gear-type slot BTISGW leaky-wave antenna array. Background Art

[0002] The advent of the 5G era has made various mobile terminals have higher and higher requirements for the coverage and transmission rate of wireless signals, and spectrum resources are becoming more and more precious. A single antenna greatly limits the transmission rate and gain of the antenna, and does not make full use of spectrum resources, and cannot meet people's demand for high-speed transmission. Antenna array technology can greatly improve the above situation. It can not only strengthen and improve the radiation field and directivity of a single antenna, but also improve the antenna gain and the intensity of the radiation field, so that the spectrum resources can play the maximum value. Leaky wave antennas have the advantages of simple structure and low processing cost. Combined with antenna array technology, they become leaky wave antenna arrays. This antenna array can not only effectively improve the gain of a single antenna, but also improve the radiation efficiency and improve the directivity of the antenna. More importantly, the curved terminal leaky wave antenna array is smaller in size, easier to process and lower in cost. The curved terminal leaky wave antenna array can not only maintain the same performance as the traditional leaky wave antenna array, including effectively increasing the coverage of wireless signals and improving the frequency space reuse rate, but also reduce the size and processing cost. It has broad research potential in the modern society with advanced communication technology.

[0003] In recent years, the integrated substrate gap waveguide (ISGW) technology has been proposed. This waveguide technology is based on a multi-layer PCB dielectric board. The initial ISGW consists of two layers of PCB dielectric boards. A layer of copper is applied on the upper surface of the upper PCB dielectric board to form a perfect electric conductor (PEC). A microstrip line is printed on the lower PCB dielectric board. The microstrip line has a series of metallized vias connected to the metal ground below to form a ridge-like structure. The two sides of the microstrip line are periodic mushroom structures to form a perfect magnetic conductor (PMC). This ISGW structure is called a ridge ISGW. Due to the formation of EBG between PEC and PMC, electromagnetic waves (quasi-TEM waves) can only propagate along the microstrip line. However, since the microstrip line and the mushroom structure in the ridge ISGW are on the same PCB board, the microstrip line will be restricted by the mushroom structure and cannot be flexibly laid out and routed, which has limitations in practical applications.

[0004] The integrated substrate gap waveguide (ISGW) was later improved to consist of three layers of PCB dielectric boards. The upper surface of the upper PCB dielectric board is covered with a layer of copper to form a perfect electric conductor (PEC), and a microstrip line is printed on the lower surface to transmit electromagnetic energy. The bottom PCB dielectric board is fully printed with mushroom-shaped periodic structures to form a perfect magnetic conductor (PMC). A blank dielectric board (intermediate dielectric board) is inserted between the upper and bottom dielectric boards to separate the upper and bottom dielectric boards. Due to the partition of the intermediate dielectric board, the microstrip line can be laid out more flexibly without worrying about being restricted by the periodic structure. When this integrated substrate gap waveguide (ISGW) works, the quasi-TEM wave will propagate along the microstrip line in the dielectric substrate between the microstrip line and the PEC. This working mode is very similar to the microstrip line buried in the dielectric. Similarly, an EBG will be generated between the PEC and the PMC to prevent the electromagnetic wave from propagating or "leaking" in other directions to ensure that the quasi-TEM wave is only transmitted along the microstrip line.

[0005] The existing leaky wave antenna array designed based on PCB technology has the problems of complex structure, large size, high cost and weak electromagnetic shielding performance. Summary of the invention

[0006] The purpose of the present invention is to provide a gear-type slot BTISGW leaky wave antenna array in response to the above-mentioned problems. The present invention radiates electromagnetic signals by setting a gear-shaped slot and adopts the integrated substrate gap waveguide ISGW technology of a three-layer PCB dielectric board structure to design a curved terminal leaky wave antenna array, thereby solving the problems of complex structure, large size, high cost and poor electromagnetic shielding performance of the existing leaky wave antenna array designed based on PCB technology.

[0007] The technical solution adopted by the present invention is as follows:

[0008] A gear-type slot BTISGW leaky wave antenna array includes an electromagnetic bandgap structure array, an antenna transmitting structure is arranged above the electromagnetic bandgap structure array; the antenna transmitting structure includes an upper dielectric plate, a curved terminal load is arranged on the lower surface of the upper dielectric plate, and a first copper clad layer is arranged on the upper surface of the upper dielectric plate; a plurality of slot units are opened on the first copper clad layer, and the slot units are used to radiate electromagnetic waves out of space. The curved terminal load is used to absorb a small amount of electromagnetic energy generated by reflection.

[0009] Furthermore, the present invention discloses a preferred structure of a gear-type slot BTISGW leaky wave antenna array, wherein the curved terminal load is in an arch shape, and two parallel lines of the curved terminal load are arranged directly below the slot unit; the curved terminal load is used to absorb a small amount of electromagnetic energy generated by reflection when the antenna is working.

[0010] Furthermore, the slot unit includes two gear-shaped slots, which can increase the ability of electromagnetic waves to radiate outward into space, thereby improving the antenna gain and radiation efficiency. The gear-shaped slot includes a plurality of teeth, and the teeth are parallel slots. The two slots in each slot unit are 14.0 mm apart, and the spacing between each slot unit is 7.5 mm.

[0011] Furthermore, a radiation unit is arranged above the antenna transmitting structure, and the radiation unit includes a top dielectric plate. The top dielectric plate must be present and is used to increase the gain of the antenna and improve the matching effect of the antenna.

[0012] Furthermore, the end of the bent terminal load is connected to a connecting line through a microstrip line connection portion, the connecting line is connected to a microstrip line head, the microstrip line head is connected to a microstrip main line, the microstrip main line is connected to a microstrip line, and the microstrip line is connected to a port; the port is used to connect a coaxial probe excitation source. The distance between the port and the physical center of the microstrip line is 9.0 mm. The distance between the physical center of the microstrip line and the center of the nearest gap unit is 22.6 mm.

[0013] Furthermore, an intermediate dielectric plate is provided between the electromagnetic bandgap structure array and the antenna radiating structure, and the intermediate dielectric plate is used to isolate the bending terminal load from the electromagnetic bandgap structure array.

[0014] Furthermore, the electromagnetic bandgap structure array comprises a lower dielectric plate, a lower surface of the lower dielectric plate is provided with a second copper clad layer, and an upper surface of the lower dielectric plate is provided with a plurality of annular circular patches.

[0015] Furthermore, a metal via is opened on the lower dielectric board below the circular patch; a metal layer is provided on the inner wall of the metal via; the lower end of the metal layer of the metal via is connected to the second copper cladding layer; and the upper end of the metal layer of the metal via is connected to the inner hole edge of the circular patch.

[0016] Furthermore, the lower dielectric board, the middle dielectric board, the upper dielectric board, and the top dielectric board are sequentially bonded from bottom to top to form a whole; the second copper clad layer is used to connect the power ground. The upper dielectric board, the middle dielectric board, the lower dielectric board, the first copper clad layer printed on the upper dielectric board, and the feeding microstrip line composed of a microstrip line, a microstrip line connection part, a connecting line, a microstrip line head, a microstrip main line, and a bent terminal load, the mushroom-shaped EBG array structure made on the lower dielectric board, and the second copper clad layer printed on the lower dielectric board constitute an integrated substrate gap waveguide ISGW structure.

[0017] In summary, due to the adoption of the above technical solution, the beneficial effects of the present invention are:

[0018] 1. By setting up this device, the size of the antenna can be greatly reduced, the electromagnetic shielding performance can be improved, and the antenna efficiency can be improved;

[0019] 2. By setting up this device, the bandwidth of the antenna can be increased, and spatial beam scanning in the forward quadrant can be achieved;

[0020] 3. By setting a curved terminal load to absorb a small amount of electromagnetic energy generated by reflection, the gain and radiation efficiency can be improved. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] Figure 1 It is a schematic diagram of the structure of the gear-type slot BTISGW leaky wave antenna array of the present invention.

[0022] Figure 2 It is a schematic diagram of the upper surface of the upper dielectric plate of the gear-type slot BTISGW leaky wave antenna array of the present invention.

[0023] Figure 3 It is a schematic diagram of the lower surface of the upper dielectric plate of the gear-type slot BTISGW leaky wave antenna array of the present invention.

[0024] Figure 4 It is a schematic diagram of the upper surface of the lower dielectric plate of the gear-type slot BTISGW leaky wave antenna array of the present invention.

[0025] Figure 5 It is a schematic diagram of the lower surface of the lower dielectric plate of the gear-type slot BTISGW leaky wave antenna array of the present invention.

[0026] Figure 6 It is the return loss of the gear-type slot BTISGW leaky wave antenna array of the present invention.

[0027] Figure 7 It is the total gain of the gear-type slot BTISGW leaky wave antenna array of the present invention.

[0028] Figure 8 It is the scanning angle of the gear-type slot BTISGW leaky wave antenna array of the present invention.

[0029] Fig. 9 It is the radiation efficiency of the gear-type slot BTISGW leaky wave antenna array of the present invention.

[0030] Fig.10 It is a detailed structural diagram of EBG of the present invention;

[0031] Markings in the figure: 1 is the lower dielectric board, 2 is the second copper layer, 3 is the metal via, 4 is the circular patch, 5 is the middle dielectric board, 6 is the upper dielectric board, 7 is the curved terminal load, 8 is the first copper layer, 9 is the gap unit, 10 is the top dielectric board, 11 is the microstrip line, 12 is the port, 13 is the microstrip line connection part, 14 is the connecting line, 15 is the microstrip line end, and 16 is the microstrip main line. DETAILED DESCRIPTION

[0032] The present invention will be described in detail below in conjunction with the accompanying drawings.

[0033] In order to make the purpose, technical solution and advantages of the present invention more clearly understood, the present invention is further described in detail below in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not intended to limit the present invention.

[0034] Among them, BTISGW refers to bent terminal integrated substrate gap waveguide, BTISGW refers to bent terminal integrated substrate gap waveguide, PMC refers to perfect magnetic conductor, EBG refers to mushroom-shaped array structure, and ISGW refers to integrated substrate gap waveguide structure.

[0035] Embodiment 1:

[0036] like Figure 1-Figure 10 As shown, the present invention includes a gear-type slot BTISGW leaky wave antenna array, including four layers of dielectric plates: a top dielectric plate 10, an upper dielectric plate 6, a middle dielectric plate 5, and a lower dielectric plate 1, wherein:

[0037] a. The top dielectric plate 10 is an essential radiating unit of the antenna array. In addition to being used to increase the gain of the antenna, it is also used to improve the matching effect of the antenna;

[0038] b. The curved terminal load 7 is a curved microstrip line and is also an indispensable curved terminal load for the antenna. It is located at the other end of the antenna array and is used to absorb a small amount of electromagnetic energy generated by reflection when the antenna is working;

[0039] c. The upper surface of the upper dielectric plate 6 is printed with a first copper-clad layer 8; N slot units 9 are etched on the first copper-clad layer 8, where N is a positive integer, and each slot unit includes two gear-shaped slots; the lower surface is printed with a feeding microstrip line consisting of a microstrip line 11, a microstrip line connection portion 13, a connecting line 14, a microstrip line head 15, a microstrip main line 16, and a bent terminal load 7, which runs through the entire upper dielectric plate 6; the port 12 of the feeding microstrip line consisting of the microstrip line 11, the microstrip line connection portion 13, the connecting line 14, the microstrip line head 15, the microstrip main line 16, and the bent terminal load 7 is used to connect a coaxial probe excitation source;

[0040] d. The middle dielectric plate 5 separates the upper dielectric plate 6 and the lower dielectric plate 1, so that a gap is formed between the upper dielectric plate 6 and the lower dielectric plate 1, which facilitates the layout of the microstrip transmission line;

[0041] e. A circular patch 4 on the upper surface of the lower dielectric plate 1 has a second copper clad layer 2 printed on the lower surface; a metal via 3 is punched in the lower dielectric plate 1, and together with the circular patch 4 on the upper surface, forms an electromagnetic band gap EBG structure array;

[0042] f. The ISGW structure consisting of the top dielectric plate 10, the upper dielectric plate 6, and the middle dielectric plate 5 is bonded together with the lower dielectric plate 1 to form a whole;

[0043] g. The first copper-clad layer 8 on the upper dielectric plate 6 and the lower surface of the lower dielectric plate 1 as the second copper-clad layer 2 are both ideal electrical conductors PEC, and the lower dielectric plate 1 is equivalent to an ideal magnetic conductor PMC;

[0044] The upper dielectric board 6, the middle dielectric board 5, the lower dielectric board 1, the first copper clad layer 8 printed on the upper dielectric board 6, and the feeding microstrip line composed of a microstrip line 11, a microstrip line connecting portion 13, a connecting line 14, a microstrip line head 15, a microstrip main line 16 and a bent terminal load 7, the mushroom-shaped EBG array structure made on the lower dielectric board, and the second copper clad layer 2 printed on the lower dielectric board 1 constitute an integrated substrate gap waveguide ISGW structure.

[0045] In this example, N=11, and the 11 slot units 9 on the upper dielectric plate 6, each slot unit includes two gear-shaped slots and are distributed directly above the feeding microstrip line composed of a microstrip line 11, a microstrip line connecting portion 13, a connecting line 14, a microstrip line end 15, a microstrip main line 16 and a bent terminal load 7; the mushroom-shaped EBG structure on the lower dielectric plate 1 is a 48×14 array. In this example, the top dielectric plate 10 is made of Rogers 4003 plate with a thickness of 0.813 mm; the upper dielectric plate 6, the middle dielectric plate 5, and the lower dielectric plate 1 are all made of Rogers RT / duroid 5880 plate with thicknesses of 0.508 mm, 0.254 mm, and 0.787 mm, respectively; simulation results show that the -10 dB impedance bandwidth of the antenna array is 24.8 GHz-28.8 GHz, and the relative bandwidth is 14.9%; spatial frequency scanning in the forward quadrant can be achieved, i.e., from 5.8° to 29.7°; the radiation efficiency is between 90% and 99.8%, and the antenna gain range is 11 dB-17 dB.

[0046] By setting up this device, the size of the antenna can be greatly reduced, the electromagnetic shielding performance can be improved, and the antenna efficiency can be improved; the bandwidth of the antenna can be increased to achieve spatial beam scanning in the forward quadrant; and by setting up a curved terminal load for absorbing energy, the gain and radiation efficiency can be improved.

[0047] Embodiment 2:

[0048] Based on Example 1, a preferred implementation of a gear-type slot BTISGW leaky wave antenna array is disclosed. The difference from the traditional leaky wave antenna array is that the other end of the antenna array does not use a power divider as a load, but instead uses a section of curved microstrip line as a terminal load to absorb a small amount of electromagnetic energy generated by reflection. In other words, the terminal load at the other end of the antenna array uses a section of curved microstrip line to absorb excess electromagnetic energy, that is, a curved terminal load 7.

[0049] The gear-type slot BTISGW leaky wave antenna array has N slot units 9 on the first copper-clad layer 8 of the upper dielectric plate 6 of the integrated substrate gap waveguide, where N is a positive integer, and each slot unit includes two gear-type slots, and a feeding microstrip line consisting of a microstrip line 11, a microstrip line connection portion 13, a connecting line 14, a microstrip line head 15, a microstrip main line 16 and a bent terminal load 7 runs through the entire upper dielectric plate 6, and the two slots in each slot unit are 14.0 mm apart, the spacing between each slot unit is 7.5 mm, and the distance between the port 12 and the physical center of the microstrip line 15 is 9.0 mm. The distance between the physical center of the microstrip line 15 and the center of the nearest slot unit is 22.6 mm.

[0050] Embodiment 3:

[0051] On the basis of Example 1, a preferred implementation of a gear-type slot BTISGW leaky wave antenna array is disclosed, wherein the top dielectric plate 10 is an indispensable radiating unit of the antenna, which is used to improve the matching effect of the antenna and increase the gain of the antenna; the feeding microstrip line composed of a microstrip line 11, a microstrip line connection part 13, a connecting line 14, a microstrip line head 15, a microstrip main line 16 and a bent terminal load 7 on the lower surface of the upper dielectric plate 6 runs through the entire upper dielectric plate 6, and when the electromagnetic wave is transmitted along the feeding microstrip line, the electromagnetic wave is gradually radiated outward through the gear-type slot; when the slot 9 is fixed and the length of the feeding microstrip line is lengthened or shortened, the return loss changes significantly. N slot units 9, N is a positive integer. Each slot unit includes two gear-type slots, which can increase the ability of electromagnetic waves to radiate outward into space, thereby improving the antenna gain and radiation efficiency.

[0052] When other parameters are fixed and the top dielectric plate 10 exists, the impedance bandwidth of the antenna is wider, the gain of the antenna is higher and the radiation efficiency is greater; when the thickness of the top dielectric plate 10 increases, the impedance bandwidth of the antenna first increases and then decreases, while the radiation efficiency of the antenna gradually increases and tends to be stable, and the antenna gain gradually decreases and tends to be stable.

[0053] When other parameters are fixed and the spacing between each slot unit 9 increases, the antenna impedance bandwidth first decreases and then increases, the highest gain shifts toward the matching end, the side lobe level decreases, the scanning angle increases, the radiation efficiency increases and tends to be stable; when other parameters are fixed and the spacing between each slot unit 9 decreases, the antenna impedance bandwidth first increases and then decreases, the highest gain shifts toward the feeding end, the side lobe level increases, and the radiation efficiency decreases; when other parameters are fixed and the distance between the center of the microstrip line 11 and the physical center of the nearest slot unit increases, the impedance bandwidth remains unchanged, the radiation efficiency remains unchanged, the antenna gain shifts toward the matching end and gradually decreases; when other parameters are fixed and the distance between the microstrip line 11 and the physical center of the nearest slot unit decreases, the impedance bandwidth remains unchanged, the radiation efficiency decreases, and the antenna gain shifts toward the feeding end and gradually decreases.

[0054] When other parameters are fixed and the number of slot units N increases, the antenna impedance bandwidth first increases and then decreases, the antenna radiation efficiency decreases, the main beam width decreases, the side lobe level increases, and the scanning angle decreases; when other parameters are fixed and the number of slot units N decreases, the antenna impedance bandwidth first decreases and then increases, the radiation efficiency increases and tends to be stable, the main beam width increases, the side lobe level decreases, and the scanning angle increases. The required number of slot units N can be selected according to the actual gain requirements.

[0055] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions and improvements made within the spirit and principle of the present invention should be included in the protection scope of the present invention.

Claims

1. A gear-type slot BTISGW leaky wave antenna array, characterized in that: The invention comprises an electromagnetic bandgap structure array, wherein an antenna transmitting structure is arranged above the electromagnetic bandgap structure array; the antenna transmitting structure comprises an upper dielectric plate (6), a curved terminal load (7) is arranged on the lower surface of the upper dielectric plate (6), and a first copper clad layer (8) is arranged on the upper surface of the upper dielectric plate (6); a plurality of slot units (9) are opened on the first copper clad layer (8), and the slot units (9) are used to radiate electromagnetic waves; the curved terminal load (7) is in the shape of an arch, and two parallel lines of the curved terminal load (7) are arranged directly below each slot unit (9), and each slot unit (9) is provided with a plurality of slot units (9) on the upper surface of the upper dielectric plate (6); Each slot unit (9) comprises two gear-shaped slots; the gear-shaped slot comprises a plurality of teeth, wherein the teeth are parallel slots; a radiation unit is arranged above the antenna transmitting structure, wherein the radiation unit comprises a top dielectric plate (10); the end of the bent terminal load (7) is connected to a connecting line (14) through a microstrip line connecting portion (13); the connecting line (14) is connected to a microstrip line head (15); the microstrip line head (15) is connected to a microstrip main line (16); the microstrip main line (16) is connected to a microstrip line (11); and the microstrip line (11) is connected to a port (12).

2. A gear-type slot BTISGW leaky wave antenna array as claimed in claim 1, characterized in that: The curved terminal load (7) is used to absorb the redundant electromagnetic energy generated when the antenna is working.

3. A gear-type slot BTISGW leaky wave antenna array as claimed in claim 1, characterized in that: The top dielectric plate (10) must be present and is used to increase the gain of the antenna and improve the matching effect of the antenna.

4. A gear-type slot BTISGW leaky wave antenna array as claimed in claim 1, characterized in that: The port (12) is used for connecting a coaxial probe excitation source.

5. A gear-type slot BTISGW leaky wave antenna array as claimed in claim 4, characterized in that: An intermediate dielectric plate (5) is provided between the electromagnetic bandgap structure array and the antenna emitting structure, and the intermediate dielectric plate (5) is used to isolate the bending terminal load (7) from the electromagnetic bandgap structure array.

6. A gear-type slot BTISGW leaky wave antenna array as claimed in claim 5, characterized in that: The electromagnetic bandgap structure array comprises a lower dielectric plate (1), a second copper clad layer (2) is provided on the lower surface of the lower dielectric plate (1), and a plurality of annular circular patches (4) are provided on the upper surface of the lower dielectric plate (1).

7. A gear-type slot BTISGW leaky wave antenna array as claimed in claim 6, characterized in that: A metal via (3) is provided on the lower dielectric plate (1) below the circular patch (4); a metal layer is provided on the inner wall of the metal via (3); the lower end of the metal layer of the metal via (3) is connected to the second copper clad layer (2); and the upper end of the metal layer of the metal via (3) is connected to the inner hole edge of the circular patch (4).

8. A gear-type slot BTISGW leaky wave antenna array as claimed in claim 7, characterized in that: The lower dielectric plate (1), the middle dielectric plate (5), the upper dielectric plate (6), and the top dielectric plate (10) are sequentially adhered from bottom to top to form a whole; the second copper clad layer (2) is used to connect to the power ground.

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