High-isolation lens antenna

Abstract

The invention provides a high-isolation lens antenna which comprises a PCB patch receiving antenna and a PCB patch transmitting antenna, the PCB patch receiving antenna and the PCB patch transmitting antenna are installed on an installation base, dielectric lenses are arranged at the upper end of the PCB patch receiving antenna and the upper end of the PCB patch transmitting antenna, the PCB patch receiving antenna and the PCB patch transmitting antenna are arranged at the interval of a wavelength, and the dielectric lenses are arranged at the lower end of the PCB patch receiving antenna and the upper end of the PCB patch transmitting antenna. The PCB patch receiving antenna and the PCB patch transmitting antenna are placed on a focal plane of the dielectric lens, and the upper end of the PCB patch receiving antenna and the upper end of the PCB patch transmitting antenna are provided with antenna covers. By improving the antenna isolation, emission leakage can be effectively reduced, and the performance of a radar system is improved. According to the scheme, some step-shaped structures are additionally arranged on the lens, and the flow of surface waves in a medium is reduced, so that the maximum isolation of the antenna is improved to 61dB.

Description

Technical Field

[0001] The present invention relates to the technical field of lens antennas, and particularly to a lens antenna with high isolation. Background Art

[0002] With the popularization of more and more intelligent driving vehicles, radars with the FMCW system have come into the public eye. A radar detects a target by emitting electromagnetic waves. After the antenna receives the signal reflected by the target, the system processes the signal to obtain relevant information such as the position, speed, and distance of the target. When this information meets the preset conditions, a start signal is output to start executing a preset command (such as obstacle avoidance, etc.), thereby obtaining the best cooperation efficiency. Due to the limitations of the carrier, millimeter-wave radars have strict requirements for the size of the antenna. It not only needs to meet electrical performance such as antenna gain and lobe width, but also requires the antenna to be small in size and light in weight, with special requirements for the assembly position and assembly space. At the same time, the influence of various differently shaped protective covers of the carrier on the antenna performance also needs to be considered. In order to reduce the influence of the protective cover on the antenna performance, the integrated design technology of the carrier and the antenna has emerged. As the radar frequency is getting higher and higher, lens technology has also received much attention. A lens antenna is an antenna technology that uses the refraction characteristics of electromagnetic waves in a lens medium to achieve beam forming and focusing. The transmit leakage of a radar with the FMCW mechanism is an important factor affecting the performance of the radar system, which may lead to reduced receiving sensitivity, increased false targets, and limited dynamic range. In order to effectively reduce transmit leakage and improve the performance of the radar system, challenges are posed to the isolation of the transceiver antennas. Summary of the Invention

[0003] The technical problem solved by the present invention is to provide a lens antenna with high isolation to solve the problems raised in the above background art.

[0004] The technical problem solved by the present invention is achieved by adopting the following technical solutions: A lens antenna with high isolation, comprising: a PCB patch receiving antenna and a PCB patch transmitting antenna. The PCB patch receiving antenna and the PCB patch transmitting antenna are installed on a mounting base. A dielectric lens is provided at the upper ends of the PCB patch receiving antenna and the PCB patch transmitting antenna. The PCB patch receiving antenna and the PCB patch transmitting antenna are placed at a distance of a wavelength. The PCB patch receiving antenna and the PCB patch transmitting antenna are placed on the focal plane of the dielectric lens. An antenna cover is provided at the upper ends of the PCB patch receiving antenna and the PCB patch transmitting antenna.

[0005] Furthermore, the outer surface of the dielectric lens is in a conical structure, which meets the aerodynamic performance during the movement of the carrier. The inner wall of the lens is designed in a stepped structure. The stepped structure on the inner surface weakens the wave in the coupling direction by perturbing the electric field phase and amplitude at the corresponding position, thereby improving the isolation of the antenna.

[0006] Further, the overall structure of the dielectric lens is designed to be thick in the middle and thin at both sides, and the dielectric constant of the medium used for the lens is 3.

[0007] Further, the radome is conical in shape, and its inner surface includes, but is not limited to, a stepped structure.

[0008] Further, the radome is conical in shape, and its inner surface includes, but is not limited to, a combination of stepped and arc-shaped structures.

[0009] Further, the radome is conical in shape, and its inner surface includes, but is not limited to, a combination of groove-shaped and arc-shaped structures.

[0010] Further, the radome is conical in shape, and its inner surface includes, but is not limited to, a groove-shaped structure.

[0011] Further, a cylindrical waveguide is provided outside the PCB patch receiving antenna and the PCB patch transmitting antenna, and the cylindrical waveguide is placed above the antenna and closely attached to the PCB board.

[0012] Compared with the prior art, the beneficial effects of the present invention are as follows: By improving the antenna isolation, the present invention can effectively reduce transmission leakage and improve the performance of the radar system. By adding some stepped structures to the lens, this solution reduces the flow of surface waves inside the medium, and the antenna isolation is increased to a maximum of 61 dB. BRIEF DESCRIPTION OF THE DRAWINGS

[0013] Figure 1 is a schematic structural diagram of the present invention.

[0014] Figure 2 is a schematic principle diagram of the present invention.

[0015] Figure 3 is a simulation diagram of the S parameters of the present invention.

[0016] Figure 4 is the radiation pattern of the transmitting antenna of the present invention.

[0017] Figure 5 is the radiation pattern of the receiving antenna of the present invention.

[0018] Figure 6 is a model diagram of the PCB antenna of the present invention.

[0019] Figure 7 is a schematic structural diagram of one embodiment of the present invention.

[0020] Figure 8 is another schematic structural diagram of the present invention.

[0021] Figure 9Schematic diagram of another radome structure of the present invention. Detailed implementation manners

[0022] In order to make the implementation means, creative features, achieved purposes and functions of the present invention easy to understand, the present invention will be further described below with reference to specific illustrations. In the description of the present invention, it should be noted that unless otherwise clearly specified and limited, the terms "installation", "connection", and "connection" should be understood in a broad sense. For example, it can be a fixed connection, a detachable connection, or an integral connection. It can be a mechanical connection or an electrical connection. It can be directly connected or indirectly connected through an intermediate medium, and the internal communication of two components can be achieved.

[0023] Embodiment 1

[0024] As Figures 1 - 9 shown, a high isolation lens antenna includes: a PCB patch receiving antenna 1 and a PCB patch transmitting antenna 2. The PCB patch receiving antenna 1 and the PCB patch transmitting antenna 2 are installed on a mounting base 3. A dielectric lens is provided at the upper ends of the PCB patch receiving antenna 1 and the PCB patch transmitting antenna 2. The PCB patch receiving antenna 1 and the PCB patch transmitting antenna 2 are placed 1 wavelength apart and are placed on the focal plane of the dielectric lens. An antenna cover is provided at the upper ends of the PCB patch receiving antenna 1 and the PCB patch transmitting antenna 2. The outer surface of the dielectric lens is in a conical structure to meet the aerodynamic performance during the movement of the carrier. The inner wall of the lens is designed in a stepped structure. The stepped structure on the inner surface weakens the wave in the coupling direction by perturbing the electric field phase and amplitude at the corresponding positions, thereby improving the isolation of the antenna. When the radar carrier moves, due to the friction between the lens and the air, a relatively high temperature will be generated at the sharpest top part. Therefore, while meeting the electrical performance, the overall structure of the lens is designed to be thick in the middle and thin at both sides, and the thinnest part meets the structural strength. The dielectric constant of the medium used for the lens is 3.

[0025] Embodiment 2

[0026] As Figures 1 - 9As shown in the figure, a high isolation lens antenna includes: a PCB patch receiving antenna 1 and a PCB patch transmitting antenna 2. The PCB patch receiving antenna 1 and the PCB patch transmitting antenna 2 are installed on a mounting base 3. A dielectric lens is provided at the upper ends of the PCB patch receiving antenna 1 and the PCB patch transmitting antenna 2. The PCB patch receiving antenna 1 and the PCB patch transmitting antenna 2 are placed 1 wavelength apart and are placed on the focal plane of the dielectric lens. An antenna cover is provided at the upper ends of the PCB patch receiving antenna 1 and the PCB patch transmitting antenna 2. The antenna cover has a conical shape, and the inner surface includes, but is not limited to, a stepped structure. The antenna cover has a conical shape, and the inner surface is a combination of a stepped shape and an arc-shaped structure.

[0027] Example 3

[0028] As Figures 1 - 9 shown in the figure, a high isolation lens antenna includes: a PCB patch receiving antenna 1 and a PCB patch transmitting antenna 2. The PCB patch receiving antenna 1 and the PCB patch transmitting antenna 2 are installed on a mounting base 3. A dielectric lens is provided at the upper ends of the PCB patch receiving antenna 1 and the PCB patch transmitting antenna 2. The PCB patch receiving antenna 1 and the PCB patch transmitting antenna 2 are placed 1 wavelength apart and are placed on the focal plane of the dielectric lens. An antenna cover is provided at the upper ends of the PCB patch receiving antenna 1 and the PCB patch transmitting antenna 2. The antenna cover has a conical shape, and the inner surface is a combination of a grooved shape and an arc-shaped structure.

[0029] Example 4

[0030] As Figures 1 - 9 shown in the figure, a high isolation lens antenna includes: a PCB patch receiving antenna 1 and a PCB patch transmitting antenna 2. The PCB patch receiving antenna 1 and the PCB patch transmitting antenna 2 are installed on a mounting base 3. A dielectric lens is provided at the upper ends of the PCB patch receiving antenna 1 and the PCB patch transmitting antenna 2. The PCB patch receiving antenna 1 and the PCB patch transmitting antenna 2 are placed 1 wavelength apart and are placed on the focal plane of the dielectric lens. An antenna cover is provided at the upper ends of the PCB patch receiving antenna 1 and the PCB patch transmitting antenna 2. The antenna cover has a conical shape, and the inner surface is a grooved structure.

[0031] Example 5

[0032] As Figures 1 - 9As shown in the figure, a high isolation lens antenna includes: a PCB patch receiving antenna 1 and a PCB patch transmitting antenna 2. The PCB patch receiving antenna 1 and the PCB patch transmitting antenna 2 are installed on a mounting base 3. A dielectric lens is provided at the upper ends of the PCB patch receiving antenna 1 and the PCB patch transmitting antenna 2. The PCB patch receiving antenna 1 and the PCB patch transmitting antenna 2 are placed 1 wavelength apart and are placed on the focal plane of the dielectric lens. An antenna cover is provided at the upper ends of the PCB patch receiving antenna 1 and the PCB patch transmitting antenna 2. A cylindrical waveguide is provided outside the PCB patch receiving antenna 1 and the PCB patch transmitting antenna 2, and the cylindrical waveguide is placed above the antenna and closely attached to the PCB board.

[0033] As Figure 2 shown, the principle of the present invention is as follows: The electric field generated by the antenna placed at the focal point passes through the b plane and passes through the dielectric antenna cover (lens) to reach the a plane, and the phases of the points on the a plane are equal or the difference is an integer multiple of 360°. At this time, the lens has a converging effect, making the beam width narrower (for example, in the case of the aperture size of this solution, the beam width is only 5°), and improving the antenna gain. The stepped structure on the inner surface weakens the wave in the coupling direction by perturbing the electric field phase and amplitude at the corresponding position, thereby improving the isolation of the antenna.

[0034] The antenna of the present invention is composed of 2 PCB patch antennas (1 for transmitting and 1 for receiving) + a cylindrical waveguide + a dielectric lens. Among them, the 2 circularly polarized PCB patch antennas are placed 1 wavelength apart and are placed on the focal plane of the dielectric lens. The PCB antenna is a circularly polarized patch antenna in a back-feed form and is fixed on the mounting base. The cylindrical waveguide is placed above the antenna and closely attached to the PCB board. The TE11 mode of the excited waveguide generates a circularly polarized wave, and then passes through the dielectric lens to radiate the circularly polarized electromagnetic wave. As Figure 6 shown, the PCB antenna model diagram (the black part is the PCB board, the white part is the patch antenna, and the feeding method is coaxial back-feed).

[0035] The above shows and describes the basic principles, main features and advantages of the present invention. Those skilled in the art should understand that the present invention is not limited by the above embodiments. What is described in the above embodiments and the specification only illustrates the principle of the present invention. Without departing from the spirit and scope of the present invention, the present invention will have various changes and improvements, and these changes and improvements all fall within the scope of the present invention claimed. The scope of protection claimed by the present invention is defined by the appended claims and their equivalents.

Claims

1. A high isolation lens antenna, comprising: PCB patch receiving antenna (1), PCB patch transmitting antenna (2), characterized in that: the PCB patch receiving antenna (1) and the PCB patch transmitting antenna (2) are installed on the mounting base (3), the upper ends of the PCB patch receiving antenna (1) and the PCB patch transmitting antenna (2) are provided with dielectric lenses, the PCB patch receiving antenna (1) and the PCB patch transmitting antenna (2) are placed at a distance of (1) wavelength, the PCB patch receiving antenna (1) and the PCB patch transmitting antenna (2) are placed on the focal plane of the dielectric lens, and the upper ends of the PCB patch receiving antenna (1) and the PCB patch transmitting antenna (2) are provided with radomes.

2. The high isolation lens antenna according to claim 1, characterized in that: The outer surface of the dielectric lens is in a conical structure, meeting the aerodynamic performance during the movement of the carrier. The inner wall of the lens is designed in a stepped structure. The stepped structure on the inner surface weakens the wave in the coupling direction by perturbing the electric field phase and amplitude at the corresponding position, thereby improving the isolation of the antenna.

3. The high isolation lens antenna according to claim 1, characterized in that: The overall structure design of the dielectric lens is thick in the middle and thin at both sides, and the dielectric constant of the medium used for the lens is 3.

4. A highly isolated lens antenna according to claim 1, characterized in that: The radome has a conical shape, and the inner surface includes but is not limited to a stepped structure.

5. The high isolation lens antenna according to claim 1, characterized in that: The radome has a conical shape, and the inner surface includes but is not limited to the combination of a stepped structure and an arc-shaped structure.

6. The high isolation lens antenna according to claim 1, characterized in that: The radome has a conical shape, and the inner surface includes but is not limited to the combination of a groove-shaped structure and an arc-shaped structure.

7. The high isolation lens antenna according to claim 1, characterized in that: The radome has a conical shape, and the inner surface includes but is not limited to a groove-shaped structure.

8. The high isolation lens antenna according to claim 1, characterized in that: The outside of the PCB patch receiving antenna (1) and the PCB patch transmitting antenna (2) is provided with a cylindrical waveguide, and the cylindrical waveguide is placed above the antenna and closely attached to the PCB board.

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