CN115360521B - A half-mode substrate integrated waveguide leaky-wave antenna with end radiation - Google Patents

Abstract

The invention discloses an end-to-radiation half-mode substrate integrated waveguide leaky-wave antenna which comprises a half-mode substrate integrated waveguide, an electric dipole array, a microstrip line, a transfer structure from the microstrip line to the half-mode substrate integrated waveguide and three layers of dielectric substrates, wherein the three layers of dielectric substrates are respectively a first layer of dielectric substrate, a second layer of dielectric substrate and a third layer of dielectric substrate, the half-mode substrate integrated waveguide and the transfer structure are arranged at two ends of the second layer of dielectric substrate, the electric dipole array is arranged on the first layer of dielectric substrate and the third layer of dielectric substrate, and the electric dipole array is loaded on a radiation port surface of the half-mode substrate integrated waveguide and is used for obtaining end-to-radiation beams with stable broadband gain. According to the invention, the vertical electric dipole array is loaded on the radiation port surface of the half-module substrate integrated waveguide, so that the end-to-radiation planar leaky-wave antenna can be obtained, and the antenna has the characteristics of simple structure, wide working bandwidth, small transverse size, stable gain and the like, and is suitable for the scenes of directional communication, terminal communication and the like.

Description

A half-mode substrate integrated waveguide leaky-wave antenna with end radiation

Technical Field

The invention belongs to the field of microwave and millimeter waves, relates to leaky wave antenna technology, and specifically relates to an end-radiating half-mode substrate integrated waveguide leaky wave antenna.

Background technique

Leaky wave antennas can provide high gain through a relatively simple feeding method and are a classic and widely used antenna form. The typical feature of leaky wave antennas is their frequency beam scanning characteristics, that is, the beam direction of the antenna changes with the frequency. However, this characteristic limits the use of leaky wave antennas in applications that require directional beams. There have been some studies on fixed-beam leaky wave antennas, but the additional structure designed to offset the dispersion of the transmission line increases the complexity and processing cost of the antenna.

Summary of the invention

Purpose of the invention: In order to overcome the deficiencies in the prior art, a half-mode substrate integrated waveguide leaky-wave antenna with end radiation is provided. By loading a vertically placed electric dipole array on the radiation port surface of the half-mode substrate integrated waveguide, an end-radiating planar leaky-wave antenna can be obtained. The antenna has the characteristics of simple structure, wide working bandwidth, small lateral size, stable gain, etc., and is suitable for scenarios such as directional communication and terminal communication.

Technical solution: To achieve the above-mentioned purpose, the present invention provides an end-radiating half-mode substrate integrated waveguide leaky wave antenna, comprising a half-mode substrate integrated waveguide, an electric dipole array, a microstrip line, a transition structure from the microstrip line to the half-mode substrate integrated waveguide, and a three-layer dielectric substrate, wherein the three-layer dielectric substrate is respectively a first layer dielectric substrate, a second layer dielectric substrate and a third layer dielectric substrate, the half-mode substrate integrated waveguide and the transition structure are arranged on both ends of the second layer dielectric substrate, the electric dipole array is arranged on the first layer dielectric substrate and the third layer dielectric substrate, and the electric dipole array is loaded on the radiation port surface of the half-mode substrate integrated waveguide to obtain a broadband gain-stable end-radiated beam.

Furthermore, the half-mode substrate integrated waveguide includes a first metal layer, a second dielectric layer and a second metal layer, the first metal layer, the second dielectric layer and the second metal layer are stacked in sequence, and the first metal layer, the second dielectric layer and the second metal layer are provided with uniformly arranged first metallized through holes, and the first metallized through holes penetrate the first metal layer, the second dielectric layer and the second metal layer.

Furthermore, the electric dipole array includes a first dielectric layer, a third dielectric layer, and uniformly arranged second metallized through holes penetrating the first dielectric layer and the third dielectric layer, wherein the first dielectric layer and the third dielectric layer extend laterally to form a dielectric. The dielectric in front of the electric dipole extends laterally to adjust the impedance matching and gain of the antenna.

Furthermore, the transition structure from the microstrip line to the half-mode substrate integrated waveguide is divided into two parts, namely, a transition part from the microstrip line to the half-mode substrate integrated waveguide of the transmission mode, and a transition part from the half-mode substrate integrated waveguide of the transmission mode to the half-mode substrate integrated waveguide of the leaky mode.

Furthermore, the transition structure from the microstrip line to the half-mode substrate integrated waveguide is a gradient structure, which completes the transition from the microstrip line to the half-mode substrate integrated waveguide in the transmission mode and then to the half-mode substrate integrated waveguide in the leaky mode.

Furthermore, the antenna structure is bilaterally symmetrical about the center point. Both ports of the antenna are provided with switching structures, which are respectively connected to the feeder and the matching load.

In the present invention, an electric dipole array is loaded on the radiation port surface of a half-mode substrate integrated waveguide. After the electric dipole array is loaded, the transmission constant of the half-mode substrate integrated waveguide will change by adjusting the height, period, and diameter of the metal through hole of the electric dipole, and the fast-wave structure before loading is transformed into a slow-wave structure after loading, thereby obtaining an end-radiated pencil beam.

Beneficial effect: Compared with the prior art, the present invention can obtain an end-radiating planar leaky-wave antenna by loading a vertically placed electric dipole array on the radiation port surface of the half-mode substrate integrated waveguide. By utilizing the structure of loading the electric dipole on the half-mode substrate integrated waveguide working in the leaky-wave mode, a broadband, high-gain end-radiating antenna is realized without the need for additional design structures. The antenna has the characteristics of simple structure, wide working bandwidth, small lateral size, stable gain, etc., and is suitable for scenarios such as directional communication and terminal communication.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG1 is a three-dimensional structural diagram of an end-radiating half-mode substrate integrated waveguide leaky-wave antenna according to the present invention;

FIG2 is a side view and a partially enlarged structural diagram of the end-radiating half-mode substrate integrated waveguide leaky-wave antenna of the present invention;

FIG3 is a top view and a partially enlarged structural diagram of the end-radiating half-mode substrate integrated waveguide leaky-wave antenna of the present invention;

FIG4 is a diagram of simulated and measured S parameters of the end-radiating half-mode substrate integrated waveguide leaky-wave antenna of the present invention;

FIG5 is a diagram showing the simulated and measured gains of the end-radiating half-mode substrate integrated waveguide leaky-wave antenna of the present invention, as well as a diagram showing the simulated radiation efficiency;

FIG. 6 is a simulation and measured radiation pattern of the end-radiating half-mode substrate integrated waveguide leaky-wave antenna of the present invention.

Detailed ways

The present invention is further explained below in conjunction with the accompanying drawings and specific embodiments. It should be understood that these embodiments are only used to illustrate the present invention and are not used to limit the scope of the present invention. After reading the present invention, various equivalent forms of modifications to the present invention by those skilled in the art all fall within the scope defined by the claims attached to this application.

As shown in Figures 1 to 3, the present invention provides an end-radiating half-mode substrate integrated waveguide leaky wave antenna, including a half-mode substrate integrated waveguide, a vertically placed electric dipole array, a microstrip line 8, a transition structure 7 from the microstrip line 8 to the half-mode substrate integrated waveguide, and three layers of dielectric substrates. The three layers of dielectric substrates are respectively a first layer of dielectric substrate, a second layer of dielectric substrate, and a third layer of dielectric substrate from top to bottom. The half-mode substrate integrated waveguide and the transition structure 7 are arranged on both ends of the second layer of dielectric substrate, the electric dipole array is arranged on the first layer of dielectric substrate and the third layer of dielectric substrate, and the electric dipole array is loaded on the radiation port surface of the half-mode substrate integrated waveguide to obtain a broadband gain-stable end-radiated beam.

The half-mode substrate integrated waveguide includes a first metal layer 2, a second dielectric layer 3 and a second metal layer 4, which are stacked in sequence from top to bottom, and a uniformly arranged first metallized through-hole array 12 is arranged on the first metal layer 2, the second dielectric layer 3 and the second metal layer 4, and the first metallized through-hole array 12 runs through the first metal layer 2, the second dielectric layer 3 and the second metal layer 4.

The electric dipole array includes a first layer of dielectric 1, a third layer of dielectric 5, a second metallized through-hole 6 evenly arranged throughout the first layer of dielectric 1 and the third layer of dielectric 5, and a dielectric 11 formed by the first layer of dielectric 1 and the third layer of dielectric 5 extending laterally. The dielectric 11 can serve as an impedance transformation structure between the antenna and the free space, thereby adjusting the impedance matching of the antenna.

As shown in FIG3 , the present invention provides an end-radiating half-mode substrate integrated waveguide leaky wave antenna, the antenna structure is bilaterally symmetrical about the center point, and both ports of the antenna are provided with a switching structure 7, which is respectively connected to the feeder and the matching load. The semi-mode substrate integrated waveguide is divided into a semi-mode substrate integrated waveguide 9 of a transmission mode and a semi-mode substrate integrated waveguide 10 of a leaky wave mode. The transition structure 7 from the microstrip line 8 to the semi-mode substrate integrated waveguide is also divided into two parts, namely, a transition part from the microstrip line 8 to the semi-mode substrate integrated waveguide 9 of a transmission mode, and a transition part from the semi-mode substrate integrated waveguide 9 of a transmission mode to the semi-mode substrate integrated waveguide 10 of a leaky wave mode. Both transition parts are gradual structures. The width of the signal line of the microstrip line 8 gradually widens and is connected to the upper wide side of the semi-mode substrate integrated waveguide 9 of the transmission mode. The width of the metal wall (composed of the first metallized through-hole array 12) of the semi-mode substrate integrated waveguide 9 of the transmission mode gradually narrows and transitions to the semi-mode substrate integrated waveguide 10 of the leaky wave mode, thereby completing the transition from the microstrip line 8 to the semi-mode substrate integrated waveguide 9 of the transmission mode, and then to the semi-mode substrate integrated waveguide 10 of the leaky wave mode.

In the present invention, an electric dipole array is loaded on the radiation aperture of a half-mode substrate integrated waveguide. After the electric dipole array is loaded, the transmission constant of the half-mode substrate integrated waveguide will change. The height, period, and diameter of the metal through hole of the electric dipole are adjusted to appropriate values, so that the half-mode substrate integrated waveguide is transformed from a fast-wave structure before loading to a slow-wave structure after loading. It can be known from the working principle of a leaky-wave antenna that when the phase constant of the leaky-wave structure is greater than or equal to the phase constant of the free space, the leaky-wave structure can obtain an end-radiated pencil beam.

Based on the above scheme, in order to verify the effect of the leaky wave antenna provided by the present invention, the following simulation test is carried out in this embodiment, and the specific results are as follows:

FIG4 shows the simulated and measured S parameters of the antenna. It can be seen that the reflection coefficient of the antenna is less than -10 dB and the transmission coefficient is less than -5 dB in the 20.7 to 30 GHz frequency band.

As shown in FIG5 , the simulated and measured gains of the antenna, as well as the simulated radiation efficiency, it can be seen that in the 22 to 28 GHz frequency band, the measured gain of the antenna is between 11.2 and 13.9 dBi, and the gain fluctuation is less than 3 dB; within the 3 dB gain bandwidth, the radiation efficiency of the antenna is about 80%.

Figure 6 shows the simulated and measured radiation patterns of the E-plane and H-plane of the antenna at 25 GHz. It can be seen that the measured results are in good agreement with the simulation results. The cross polarization of the antenna is lower than -10 dB, and the front-to-back ratio is greater than 20 dB.

Table 1 shows the performance comparison between the existing leaky wave antenna and the leaky wave antenna of the present invention. Through the comparison, it can be seen that the impedance bandwidth and 3dB gain bandwidth of the leaky wave antenna of the present invention are wider, and due to the use of a half-mode substrate integrated waveguide structure, the width of the antenna is smaller. By loading an electric dipole array on the radiation port surface of the half-mode substrate integrated waveguide, the antenna can not only generate a directional radiation beam pointing to 90° (i.e., end-to-end), but also generate a higher gain at a shorter length.

Table 1 Performance comparison between existing leaky wave antenna and leaky wave antenna of the present invention

Claims (4)

1. The half-mode substrate integrated waveguide leaky-wave antenna is characterized by comprising a half-mode substrate integrated waveguide, an electric dipole array, a microstrip line, a transfer structure from the microstrip line to the half-mode substrate integrated waveguide and three layers of dielectric substrates, wherein the three layers of dielectric substrates are respectively a first layer of dielectric substrate, a second layer of dielectric substrate and a third layer of dielectric substrate, the half-mode substrate integrated waveguide and the transfer structure are arranged at two ends of the second layer of dielectric substrate, the electric dipole array is arranged on the first layer of dielectric substrate and the third layer of dielectric substrate, and the electric dipole array is loaded on a radiation port surface of the half-mode substrate integrated waveguide and is used for obtaining an end-direction radiation beam;

the half-mode substrate integrated waveguide comprises a first metal layer, a second layer of medium and a second metal layer, wherein the first metal layer, the second layer of medium and the second metal layer are sequentially stacked, first metallized through holes which are uniformly arranged are formed in the first metal layer, the second layer of medium and the second metal layer, and the first metallized through holes penetrate through the first metal layer, the second layer of medium and the second metal layer;

The electric dipole array comprises a first layer of medium, a third layer of medium and second metallized through holes which penetrate through the first layer of medium and the third layer of medium and are uniformly arranged, and the first layer of medium and the third layer of medium extend to the side to form the medium.

2. The half-mode substrate integrated waveguide leaky-wave antenna of claim 1, wherein the transfer structure of the microstrip line to the half-mode substrate integrated waveguide is divided into two parts, namely a transfer part of the microstrip line to the half-mode substrate integrated waveguide of a transmission mode and a transfer part of the half-mode substrate integrated waveguide of the transmission mode to the half-mode substrate integrated waveguide of a leaky-wave mode.

3. The half-mode substrate integrated waveguide leaky-wave antenna of claim 2, wherein the transfer structure from the microstrip line to the half-mode substrate integrated waveguide is a gradual change structure, and the transfer from the microstrip line to the half-mode substrate integrated waveguide of the transmission mode to the half-mode substrate integrated waveguide of the leaky-wave mode is completed.

4. The end-radiating half-mode substrate integrated waveguide leaky-wave antenna of claim 1, wherein the antenna structure is side-to-side symmetric about the center point.