Substrate integrated waveguide periodic leaky-wave antenna with stable X-band gain

Abstract

The invention provides the substrate integrated waveguide periodic leaky-wave antenna with stable X-band gain. The antenna structure comprises a dielectric plate, a metal transmission band, an antenna radiation slot, a feed port, a feed connector, a metal via hole, a metal upper surface and a metal floor. The antenna radiation slot is composed of unit radiation slots which are periodically arranged in the Y direction, and each unit radiation slot is composed of two rocket-shaped radiation slots which are arranged in an overturning, staggered and stacked mode. And the antenna radiation slot and the metal floor are respectively arranged on the upper surface and the lower surface of the dielectric plate. The feed connector comprises a center feed probe and an outer conductor, and the center feed probe and the outer conductor are connected with the metal transmission band and the metal floor respectively. The antenna is a periodic leaky-wave antenna, stability and wide coverage of beam radiation gain are realized, the antenna adopts a substrate integrated waveguide structure as a microwave transmission structure, the structure is simple, the antenna is easy to manufacture, and the antenna has wide application prospects in military and civilian use scenes such as wireless communication, radar systems and satellite navigation.

Description

Technical Field

[0001] The present invention relates to the fields of high-resolution radar and satellite communication, and more specifically, to a substrate-integrated waveguide periodic leaky-wave antenna with stable X-band gain. Background Art

[0002] Antennas are used to receive and send electromagnetic wave signals, and they play an extremely important role in fields such as mobile communications and radar. Leaky wave antennas have the inherent characteristic of beam scanning with frequency, which is usually a disadvantage for point-to-point communications, but a great advantage for scanning applications such as microwave radiometers. In actual communication systems, antennas must not only have the characteristics of miniaturization, but also be able to maintain stable communication in the face of complex geographical environments and harsh conditions. The stability of antenna gain directly affects the stability of signal transmission. Antennas with unstable gain show unstable working power in different working frequency bands, which directly leads to unstable signal data transmission and reception. For example, low power will cause the back-end devices to be unable to work in the linear region, and high power will cause problems such as RF link blocking. Therefore, it is necessary to design a substrate-integrated waveguide periodic leaky wave antenna with stable X-band gain.

[0003] The substrate integrated waveguide leaky wave antenna is a traveling wave antenna. The electromagnetic wave propagating on the substrate integrated waveguide structure is a fast wave, which has the inherent characteristic of beam scanning with frequency. It also has the advantages of low profile, easy feeding and easy integration, which is extremely convenient in the antenna manufacturing process. The radiation range of the uniform leaky wave antenna can only work in the forward direction, which is difficult to meet the needs of fields such as wireless communications and radar. The periodic leaky wave antenna meets the requirements of the above fields and can realize the radiation of the antenna from backward to forward, with a larger radiation range. However, the periodic leaky wave antenna also has disadvantages. The open stopband phenomenon will appear in its radiation process, resulting in a sharp attenuation of the gain in the side-fire direction. The overall gain shows a large fluctuation phenomenon, which is not conducive to the continuous radiation of the antenna. Summary of the invention

[0004] In order to solve the above-mentioned problems of small antenna radiation range and unstable gain, the present invention proposes a substrate-integrated waveguide periodic leaky-wave antenna with stable X-band gain, which can achieve a larger radiation range and stable radiation gain.

[0005] The technical solution adopted by the present invention to solve the problem is:

[0006] The present invention provides a substrate-integrated waveguide periodic leaky wave antenna with stable gain in the X band. The antenna structure includes a dielectric plate, an antenna radiation slot, a metal transmission belt, a feed port, a feed connector, a metal via, a metal upper surface and a metal floor. The antenna radiation slot is composed of unit radiation slots periodically arranged along the Y direction, and the unit radiation slot is composed of two rocket-shaped radiation slots that are flipped and staggered along the X direction. The antenna radiation slot is arranged on the upper surface of the dielectric plate, and the metal floor is arranged on the lower surface of the dielectric plate. The feed connector is located at the center of both sides of the metal floor. The feed connector includes a central feed probe and an outer conductor, the central feed probe is connected to the feed port arranged on the metal transmission belt, and the outer conductor is connected to the metal floor.

[0007] Preferably, the medium of the medium plate is a solid medium.

[0008] Preferably, the dielectric plate is a rectangular parallelepiped.

[0009] Preferably, the metal floor and the metal conveyor belt are planar structures and are in close contact with the dielectric plate.

[0010] Preferably, the upper part of the rocket-shaped radiation slot is an isosceles right triangle structure, and the lower part is composed of two parallel rectangles, wherein the rectangles are located at the two side edges of the isosceles right triangle and are perpendicular to the base of the isosceles right triangle.

[0011] Preferably, the rocket-shaped radiation slots are flipped and stacked in an alternating manner.

[0012] The beneficial effects of the present invention are:

[0013] The present invention provides a periodic leaky wave antenna with a rocket-shaped radiation slot structure with flipped and staggered arrangement, which has a simple structure and is easy to process. The present invention introduces a pair of identical rocket-shaped radiation slots into a unit periodic structure, then adjusts the size and position of the rocket-shaped radiation slots, and performs impedance matching, eliminates the open stop band in the X-band to achieve the effect of gain stable large-angle continuous radiation, meets the requirements of mobile communications and radar and other fields, and provides a feasible technical solution for the design of microwave radiation radiometer antennas. BRIEF DESCRIPTION OF THE DRAWINGS

[0014] The accompanying drawings are only used for illustrative purposes and should not be construed as limiting the present patent.

[0015] Figure 1 is a front schematic diagram of an embodiment of the present invention;

[0016] Figure 2 is a schematic diagram of the back side of an embodiment of the present invention;

[0017] Figure 3 is a side schematic diagram of an embodiment of the present invention;

[0018] Figure 4 is a schematic diagram of the front dimensions of an embodiment of the present invention;

[0019] Figure 5 It is a partial schematic diagram of the front dimensions of an embodiment of the present invention;

[0020] Figure 6 is S of the embodiment of the present invention 11 Reflection coefficient graph;

[0021] Figure 7 is a graph of phase constant and attenuation constant of an embodiment of the present invention;

[0022] Figure 8 is a radiation pattern of an embodiment of the present invention.

[0023] Figure numerals: 1. dielectric plate; 2. metal transmission belt; 3. unit radiation slot; 4. metal via; 5. metal upper surface; 6. feeding port; 7. metal floor; 8. outer conductor; 9. center feeding probe. DETAILED DESCRIPTION

[0024] The present invention is described in detail below with reference to the accompanying drawings and embodiments.

[0025] Embodiment 1, as Figure 1-Figure 3 It is a schematic diagram of a substrate-integrated waveguide periodic leaky-wave antenna with stable X-band gain provided by the present invention, wherein the antenna comprises a dielectric plate 1, a metal transmission belt 2, an antenna radiation slot, a metal via 4, a metal upper surface 5, a feed port 6, a metal floor 7 and a feed connector.

[0026] The metal transmission belt 2 is distributed at the center of both sides of the metal upper surface 5 of the dielectric plate 1 and connected thereto. The antenna radiation slot is composed of unit radiation slots 3 periodically arranged along the Y direction. The unit radiation slot 3 is composed of two rocket-shaped radiation slots that are flipped and stacked to form the unit radiation slot 3. The antenna radiation slot is located at the center of the two rows of metal vias 4 and is distributed on the upper and lower sides of the dielectric plate 1 with the metal floor 7. The feed connector is composed of an outer conductor 8 and a central feed probe 9. The outer conductor 8 is connected to the metal floor 7, and the central feed probe 9 is connected to the feed port 6 on the metal transmission belt.

[0027] In this embodiment, the dielectric plate 1 is a rectangular parallelepiped structure, and the interior of the dielectric plate 1 is a solid medium. In this embodiment, the material of the dielectric plate 1 is Rogers 5880. In this embodiment, the unit radiation slot 3 is made by etching, and the metal transmission belt 2, the metal upper surface 5 and the metal floor 7 are printed by surface copper coating.

[0028] like Figure 4 and Figure 5 As shown, the specific structure of the antenna of the present invention is as follows:

[0029] (1) Each periodic structural unit is composed of a pair of rocket-shaped radiation slots, which are turned over and stacked to form a unit radiation slot 3. The rocket-shaped radiation slot can be divided into two parts, the upper part is an isosceles right triangle, and the lower part is two parallel rectangles located on the two side edges of the isosceles right triangle, and the lower part is vertically connected to the upper part.

[0030] (2) The antenna radiation slot of the present invention is composed of seven pairs of unit radiation slots 3, each periodic structure includes two rows of metal vias, and the unit radiation slot 3 is located in the center of the two rows of metal vias.

[0031] In the embodiment, some parameters are related to the wavelength corresponding to the center frequency of the antenna working frequency band. The wavelength calculation method is as follows.

[0032] The calculation formula of the equivalent dielectric constant of microstrip line is as follows:

[0033]

[0034] Where h is the thickness of the dielectric plate, W1 is the width of the microstrip transmission strip, ε r is the relative dielectric constant of the dielectric plate, ε e is the effective dielectric constant of the microstrip line. Therefore, its corresponding phase velocity v p for:

[0035]

[0036] Where c is the speed of light.

[0037] The wavelength λ at the center frequency f is obtained g for:

[0038]

[0039] like Figure 4 and Figure 5 As shown. The following are the preferred size values ​​for the better results obtained after debugging and optimization in this embodiment. The dielectric plate 1 used in this embodiment is Rogers 5880, and the corresponding dielectric constant ε r=2.2, loss tangent is 0.0009, dielectric plate 1 thickness h = 1.0mm, its length is L3 = 139.0mm, width is W3 = 20.5mm, equivalent rectangular waveguide width W4 = 15mm. Metallized vias d1 = 0.9mm, d2 = 1mm. Metal transmission belt length L1 = 8.0mm, L2 = 13.5mm, width W1 = 1mm, W2 = 3.1mm. The length of the isosceles right triangle in the upper part of the rocket-shaped radiation slot is L5 = 9.25mm, the length of the single rectangle in the lower part is L6 = 3.5mm, the width W5 = 1.2mm, and the two rectangles are 8.05mm apart. The vertices of the rocket-shaped radiation slot are 13.5mm apart in the X direction and 4mm apart in the Y direction. In addition, L4 = 6.85mm, W s1 =0.75mm.

[0040] The S of the invented antenna 11 The reflection coefficient is Figure 6 In the operating frequency band, i.e. 8.4 GHz to 12.0 GHz, S 11 <-10dB, which meets the requirements of engineering applications and the antenna radiation performance is good.

[0041] The phase constant and attenuation constant curves of the antenna of the invention are shown in Figure 7 As shown in the figure, continuous scanning without jitter in the cross-beam direction is achieved within the working frequency band. Figure 8 It can be seen that the main beam of the antenna in the embodiment of the present invention realizes scanning from -52° to 44°, covering a scanning range of 96°, and the gain fluctuation can be kept within 1 dB from -32° to 44°. The antenna of the present invention has a large radiation range and a relatively stable gain.

[0042] The above embodiments are only preferred embodiments for illustrating the present invention and are not intended to limit the present invention. For those skilled in the art, any modification, equivalent substitution and improvement made within the spirit and principle of the present invention should be included in the protection scope of the claims of the present invention.

[0043] Although embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that various changes, modifications, substitutions and variations may be made to the embodiments without departing from the principles and spirit of the present invention, and that the scope of the present invention is defined by the appended claims and their equivalents.

Claims

1. An X-band gain-stable substrate-integrated waveguide periodic leaky-wave antenna, characterized in that: The invention comprises a dielectric plate (1), a metal transmission belt (2), an antenna radiation slot, a metal via (4), a metal upper surface (5), a metal floor (7), a feed port (6) and a feed connector; the antenna radiation slot is composed of unit radiation slots (3) periodically arranged along the Y direction, and the unit radiation slot (3) is composed of two rocket-shaped radiation slots that are flipped and arranged in an interlaced manner; the antenna radiation slot and the metal floor (7) are respectively tightly fitted on both sides of the dielectric plate (1); the feed connector comprises an outer conductor (8) and a central feed probe (9), the outer conductor (8) is connected to the metal floor (7), and the central feed probe (9) is connected to the feed port (6) arranged on the metal transmission belt (2).

2. The X-band gain-stabilized substrate integrated waveguide periodic leaky-wave antenna according to claim 1, characterized in that: The medium inside the medium plate (1) is a solid medium.

3. The X-band gain-stabilized substrate integrated waveguide periodic leaky-wave antenna according to claim 1, characterized in that: The unit radiation slot (3) is composed of two rocket-shaped radiation slots that are turned over and arranged in an interlaced manner along the X direction. The upper half of the rocket-shaped radiation slot is an isosceles right triangle structure, and the lower half is composed of two mutually parallel rectangles, which are located on the two side edges of the isosceles right triangle and are perpendicular to the base of the isosceles right triangle.

4. The X-band gain-stabilized substrate integrated waveguide periodic leaky-wave antenna according to claim 1, characterized in that: The vertices of the two rocket-shaped radiation slots in the unit radiation slot (3) are 13.5 mm apart in the X direction and 4 mm apart in the Y direction.

5. The X-band gain-stabilized substrate integrated waveguide periodic leaky-wave antenna according to claim 1, characterized in that: The antenna radiation slot is composed of unit radiation slots (3) periodically arranged along the Y direction, and the number of periods is 7.

Images