Periodic substrate integrated waveguide leaky-wave antenna with staggered umbrella-shaped slots and large scanning angle

Abstract

The invention provides a periodic large-scanning-angle substrate integrated waveguide leaky-wave antenna with staggered umbrella-shaped slots. The antenna structure comprises a dielectric plate, a metal transmission band, an antenna radiation slot, a feed connector, a metal via hole, a metal upper surface and a metal floor. The antenna radiation slot is formed by unit radiation slots which are periodically arranged along the Y direction, and each unit radiation slot is formed by overturning, staggering and stacking a pair of umbrella-shaped radiation slots. 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 is located in the center of the two sides of the dielectric plate and 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, wide coverage of antenna radiation can be achieved, the antenna transmission structure adopts a substrate integrated waveguide structure, the structure is simple, the manufacturing cost is low, and the antenna has wide application prospects in wireless communication, radar systems and other scenes.

Description

Technical Field

[0001] The invention relates to the field of microwave detection, and more specifically to a substrate-integrated waveguide leaky-wave antenna with a periodic large scanning angle and staggered umbrella-shaped slots. Background Art

[0002] The upper and lower metal surfaces of the substrate integrated waveguide serve as the wide wall of the waveguide, and the two rows of embedded metalized through holes serve as the narrow wall of the waveguide. Its wave guiding characteristics are similar to those of traditional rectangular waveguides, and the main mode is quasi-TE 10 It has the advantages of low cost, light weight, easy integration and low loss, and is widely used in microwave and millimeter wave circuit systems.

[0003] Leaky wave antennas have the characteristic of beam scanning with frequency. Microwave radiometer antennas receive and record microwave thermal radiation signals of objects to achieve the purpose of microwave radiation detection. Therefore, leaky wave antennas are often used in microwave radiometer antennas, making microwave radiometer antennas more and more used in fields such as mobile communications and radar. In actual application scenarios, antennas must not only meet the requirements of lightweight, but also meet the most basic requirements of stable operation in harsh working environments to ensure the normal operation of the project. Antenna gain and radiation scanning angle are crucial to the performance of wireless communication systems and radar systems. High gain and large radiation scanning angle can ensure the reliability and sensitivity of system performance. Leaky wave antennas can be divided into uniform and periodic leaky wave antennas. The biggest difference is that periodic leaky wave antennas can scan from backward to forward, which means that a larger radiation scanning angle can be achieved. However, periodic leaky wave antennas have an open stopband phenomenon, which causes the antenna gain to drop sharply in the side-fire direction, and cannot achieve continuous beam scanning from backward to forward. Summary of the invention

[0004] In order to solve the problem of open stop band in the above-mentioned periodic leaky-wave antenna, the present invention proposes a periodic large scanning angle substrate integrated waveguide leaky-wave antenna with staggered umbrella-shaped slots, which can be used to realize continuous beam scanning at a large scanning angle.

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

[0006] The present invention provides a substrate-integrated waveguide leaky wave antenna with a periodic large scanning angle and staggered umbrella-shaped slots. The antenna structure includes a dielectric plate, an antenna radiation slot, a metal transmission belt, 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 umbrella-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 ends of the dielectric plate. The feed connector includes a central feed probe and an outer conductor, and the central feed probe and the outer conductor are respectively connected to the metal transmission belt and 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 half of the umbrella-shaped radiation slot is an isosceles right triangle structure, and the lower half is a rectangular structure that is perpendicular to the base of the isosceles right triangle.

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

[0012] Compared with the prior art, the present invention has the following beneficial effects:

[0013] The present invention provides a periodic leaky wave antenna with reversed and staggered umbrella-shaped radiation slots, which is low in cost, lightweight, easy to integrate and low in loss. The present invention introduces a pair of identical umbrella-shaped radiation slots into a unit periodic structure, then adjusts the size and position of the umbrella-shaped radiation slots, and performs impedance matching, eliminates the open stop band in the 9.0GHz to 13.8GHz band to achieve a large beam scanning angle and a beam continuous scanning effect, meets the requirements of wireless communication systems and radar systems, 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. outer conductor; 7. metal floor; 8. center feed 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 1-3 Shown is a schematic diagram of a substrate-integrated waveguide leaky-wave antenna with a periodic large scanning angle and staggered umbrella-shaped gaps 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 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 umbrella-shaped radiation slots that are stacked and turned over. 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 6 and a central feed probe 8. The outer conductor 6 is connected to the metal floor 7, and the central feed probe 8 is connected to the metal transmission belt 2.

[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 umbrella-shaped radiation slots, which are turned over and stacked in an interlaced manner to form a unit radiation slot 3. The umbrella-shaped radiation slot can be divided into two parts, the upper part is an isosceles right triangle structure, and the lower part is a rectangular structure, 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 = 131.0mm, width is W3 = 20.5mm, equivalent rectangular waveguide width W4 = 15mm, metallized via d1 = 1.0mm. The length of the metal transmission belt is L1 = 5.2mm, L2 = 9.5mm, width W1 = 5.6mm, W2 = 3.1mm. The waist length of the isosceles right triangle in the upper half of the umbrella-shaped radiation slot is L5 = 9.25mm, the length of the single rectangle in the lower half is L6 = 2.5mm, and the width is W5 = 0.6mm. The lower half is perpendicular to the base of the isosceles right triangle and deviates from the midpoint of the base in the Y direction by 0.35mm. The vertices of the umbrella-shaped radiation slot are 12mm apart in the X direction and 4mm apart in the Y direction. In addition, L4 = 9.25mm, W s1 =0.25mm.

[0040] The S of the invented antenna 11 The reflection coefficient is Figure 6 In the operating frequency band, i.e. 9.0 GHz to 13.8 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 of the embodiment of the present invention realizes continuous scanning from -60° to 22°, covers a scanning range of 82°, and has no obvious fluctuation in gain in the broadside direction.

[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. A substrate-integrated waveguide leaky-wave antenna with periodic large scanning angle and interlaced umbrella-shaped slots, 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) and a feeding 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 umbrella-shaped radiation slots that are flipped and staggered; the antenna radiation slot and the metal floor (7) are respectively tightly fitted on both sides of the dielectric plate (1); the feeding connector comprises an outer conductor (6) and a central feeding probe (8), the outer conductor (6) is connected to the metal floor (7), and the central feeding probe (8) is connected to the metal transmission belt (2).

2. The periodic large scanning angle substrate integrated waveguide leaky wave antenna with interlaced umbrella-shaped slots according to claim 1, characterized in that: The medium inside the medium plate (1) is a solid medium.

3. The periodic substrate-integrated waveguide leaky-wave antenna with large scanning angle and interlaced umbrella-shaped slots according to claim 1, characterized in that: The unit radiation slot (3) is composed of two umbrella-shaped radiation slots that are flipped and arranged in an interlaced manner along the X direction, wherein the upper half of the umbrella-shaped radiation slot is an isosceles right triangle structure, and the lower half is a rectangular structure, and the lower half is perpendicular to the base of the isosceles right triangle and deviates from the midpoint of the base in the Y direction by 0.35 mm.

4. The periodic substrate-integrated waveguide leaky-wave antenna with large scanning angle and interlaced umbrella-shaped slots according to claim 1, characterized in that: The vertices of the two umbrella-shaped radiation slots in the unit radiation slot (3) are 12 mm apart in the X direction and 4 mm apart in the Y direction.

5. The periodic substrate-integrated waveguide leaky-wave antenna with large scanning angle and interlaced umbrella-shaped slots 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.

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