Transceiving antenna of double-end-on-fire antenna unit

Abstract

The invention discloses a transmitting and receiving antenna of a double-end-on-fire antenna unit, belongs to the technical field of antennas, and solves the problems of large target detection capability difference and weak lateral target detection capability of angular domains with different orientations in the design of a 5.8 GHz radar sensor antenna. According to the invention, two end-fire monopole antenna units are used as the transmitting and receiving ends of the transmitting and receiving antenna, the antenna units have the omnidirectional azimuth radiation characteristic, the gain coverage of the transmitting antenna and the receiving antenna in different azimuth angular domains is relatively consistent, and the consistency of the target detection capability of the radar sensor in different azimuth angular domains is effectively improved; according to the invention, the gain of the monopole antenna is low in the normal direction of the radar sensor module, and the lateral direction is the maximum direction of the radiation gain of the monopole antenna, so that the lateral target detection capability is greatly improved, the target detection range is expanded, and the omnibearing target detection requirement is met.

Description

Technical Field

[0001] The invention belongs to the technical field of antennas and relates to a transceiver antenna with a double end-fire antenna unit. Background Art

[0002] The radar sensor includes a transmitting antenna and a receiving antenna, which can transmit and receive electromagnetic wave signals. It uses the Doppler principle to detect the frequency difference between the transmitted signal and the received signal to determine whether there are moving objects around, thereby realizing target detection. Sensor radars have multiple operating frequency band series, including 5.8GHz, 24GHz, 77GHz, etc., which are used in scenes where people are present or moving. Among them, the 5.8GHz sensor radar is mainly used in the field of smart lighting, and has been widely used in lighting products such as induction bulbs and T8 tubes. It has broad application prospects in smart homes, the Internet of Things, security and other fields. At present, the commonly used 5.8GHz sensor radars mostly use dual-polarized microstrip patch antennas, which contain two orthogonal polarization ports corresponding to the receiving antenna port and the transmitting antenna port of the radar sensor. The transmission and reception of the sensor radar are realized through an orthogonal dual-polarized antenna. At the same time, the polarization orthogonality can ensure the isolation between the receiving and transmitting ports, thereby realizing the function of mobile target detection. Such as Figure 1 The beam coverage of the dual-polarized microstrip antenna unit under the existing technology is shown. The 5.8GHz radar sensor based on the dual-polarized microstrip patch antenna has the following technical disadvantages:

[0003] (1) In order to ensure the isolation of the transceiver ports, the polarizations of the receiving antenna and the transmitting antenna are orthogonal at 90°. In the angular domain parallel to the polarization of the transmitting antenna, the transmission of the transmitting antenna is its main polarization component, and the transmission signal strength is large, but the receiving antenna can only receive the signal through its cross-polarization component with a lower amplitude, and the received signal strength is relatively weak. In the angular domain parallel to the polarization of the receiving antenna, the transmission of the transmitting antenna is its orthogonal cross-polarization component, and the transmission signal strength is very weak. Although the receiving antenna receives the signal through its main polarization component with a stronger amplitude, the received signal strength is still weak.

[0004] (2) The microstrip antenna is a planar side-firing antenna, and its radiation gain is strongest in the direction of its normal. For the radar sensor module, the detection distance is the longest in the direction perpendicular to the normal of the module. However, 5.8GHz radar sensors are used in application scenarios such as smart lighting. The radar sensor module is usually placed at the top of the ceiling, and the moving target usually gradually approaches the normal direction from the side. Therefore, the lateral target detection capability is more critical to the detection capability of the entire radar sensor. Therefore, the existing 5.8GHz radar sensor antenna design has problems such as large differences in target detection capabilities in different angular domains and weak lateral target detection capabilities. Summary of the invention

[0005] The technical solution of the present invention is used to solve the problem that the design of the 5.8GHz radar sensor antenna has large differences in target detection capabilities in different angular domains and weak lateral target detection capabilities.

[0006] The present invention solves the above technical problems through the following technical solutions:

[0007] A transceiver antenna with dual end-fire antenna units, with an operating frequency band of 5.7 GHz to 5.9 GHz, comprising a monopole transmitting antenna unit, a monopole receiving antenna unit, a microstrip substrate, a radar sensor chip, a first antenna unit feeder and a second antenna unit feeder;

[0008] A radar sensor chip, a first antenna unit feeder, and a second antenna unit feeder are arranged on the upper surface of the microstrip substrate. A through hole is opened on the microstrip substrate. One end of the first antenna unit feeder is connected to the RF output port of the radar sensor chip, and the other end of the first antenna unit feeder passes through the through hole to be connected to the input end of the monopole transmitting antenna unit. One end of the second antenna unit feeder is connected to the RF input port of the radar sensor chip, and the other end of the second antenna unit feeder passes through the through hole to be connected to the output end of the monopole receiving antenna unit.

[0009] A monopole transmitting antenna unit and a monopole receiving antenna unit are vertically arranged on the lower surface of the microstrip substrate; the monopole transmitting antenna unit and the monopole receiving antenna unit are parallel to the normal line of the lower surface of the microstrip substrate.

[0010] Furthermore, the monopole transmitting antenna unit and the monopole receiving antenna unit are both metal rods, and the length is one quarter of the wavelength of the central operating frequency.

[0011] Furthermore, the length of the monopole transmitting antenna unit and the monopole receiving antenna unit are both 13 mm, and the diameter of the monopole receiving antenna unit are both 2 mm.

[0012] Furthermore, the central operating frequency is 5.8 GHz.

[0013] Furthermore, the microstrip substrate is an FR4 microstrip board, and the size of the microstrip substrate is 20 mm×20 mm.

[0014] Furthermore, the first antenna unit feed line is connected to the monopole transmitting antenna unit via a feed needle, and the second antenna unit feed line is connected to the monopole receiving antenna unit via a feed needle.

[0015] Further, the working principle of the transceiver antenna is as follows:

[0016] When the radar sensor chip outputs a radio frequency signal, the radio frequency signal is input into the monopole transmitting antenna unit through the first antenna unit feeder. According to the end-fire characteristic of the monopole antenna, the radio frequency signal is radiated from the end face of the output end of the monopole transmitting antenna unit. The transmitting signal forms omnidirectional radiation in the horizontal direction, which can cover all directions of the surroundings and realize all-round coverage of the radio frequency signal.

[0017] The end face of the input end of the monopole receiving antenna unit receives the radio frequency signal reflected from the surrounding area, and sends the received signal to the radar sensor chip through the second antenna unit feeder for signal processing and target detection.

[0018] The advantages of the present invention are:

[0019] The present invention adopts two end-fired monopole antenna units as the transmitting and receiving ends of the transmitting and receiving antenna. The antenna unit has an omnidirectional radiation characteristic. The gain coverage of the transmitting antenna and the receiving antenna in different angular domains in azimuth is relatively consistent, which effectively improves the consistency of the target detection capability of the radar sensor in different angular domains in azimuth. The present invention adopts an end-fired monopole antenna with a lower gain in the normal direction of the radar sensor module, and the lateral direction is the maximum direction of its radiation gain, which greatly improves the lateral target detection capability, thereby increasing the range of target detection and meeting the needs of omnidirectional target detection. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] Figure 1 is a schematic diagram of beam coverage of a dual-polarized microstrip antenna unit under the prior art;

[0021] Figure 2 is a schematic diagram of beam coverage of a dual end-fire antenna unit according to the first embodiment of the present invention;

[0022] Figure 3 It is a structural diagram of a transceiver antenna of a dual end-fire antenna unit in embodiment 1 of the present invention;

[0023] Figure 4 It is a front view of a transceiver antenna of a dual end-fire antenna unit according to the first embodiment of the present invention;

[0024] Figure 5 is the elevation plane radiation pattern of the monopole transmitting antenna unit of the first embodiment of the present invention at a center frequency of 5.8 GHz;

[0025] Figure 6 is the azimuth plane radiation pattern of the monopole transmitting antenna unit of the first embodiment of the present invention at a center frequency of 5.8 GHz;

[0026] Figure 7 is the elevation plane radiation pattern of the monopole receiving antenna unit of the first embodiment of the present invention at a center frequency of 5.8 GHz;

[0027] Figure 8 is the azimuth plane radiation pattern of the monopole receiving antenna unit of the first embodiment of the present invention at a center frequency of 5.8 GHz;

[0028] Fig. 9 is a simulation curve diagram of the isolation between the monopole transmitting antenna unit port and the monopole receiving antenna unit port of the first embodiment of the present invention;

[0029] Figure numerals: 11, monopole transmitting antenna unit; 12, monopole receiving antenna unit; 13, microstrip substrate; 14, radar sensor chip; 151, first antenna unit feed line; 152, second antenna unit feed line. DETAILED DESCRIPTION

[0030] In order to make the purpose, technical solution and advantages of the embodiments of the present invention clearer, the technical solution in the embodiments of the present invention will be clearly and completely described below in combination with the embodiments of the present invention. Obviously, the described embodiments are part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0031] The technical solution of the present invention is further described below in conjunction with the accompanying drawings and specific embodiments:

[0032] Embodiment 1

[0033] like Figure 3-4 As shown, specifically, a transceiver antenna with dual end-fire antenna units is disclosed, with a center frequency of 5.8 GHz, including a monopole transmitting antenna unit 11, a monopole receiving antenna unit 12, a microstrip substrate 13, a radar sensor chip 14, a first antenna unit feed line 151 and a second antenna unit feed line 152;

[0034] The upper surface of the microstrip substrate 13 is provided with a radar sensor chip 14, a first antenna unit feeder 151, and a second antenna unit feeder 152. The microstrip substrate 13 is provided with a through hole. One end of the first antenna unit feeder 151 is connected to the RF output port of the radar sensor chip 14, and the other end of the first antenna unit feeder 151 is connected to the input end of the monopole transmitting antenna unit 11 through the through hole. One end of the second antenna unit feeder 152 is connected to the RF input port of the radar sensor chip 14, and the other end of the second antenna unit feeder 152 is connected to the output end of the monopole receiving antenna unit 12 through the through hole.

[0035] A monopole transmitting antenna unit 11 and a monopole receiving antenna unit 12 are vertically arranged on the lower surface of the microstrip substrate 13 ; the monopole transmitting antenna unit 11 and the monopole receiving antenna unit 12 are parallel to the normal line of the lower surface of the microstrip substrate 13 .

[0036] Furthermore, the first antenna unit feed line 151 is connected to the monopole transmitting antenna unit 11 through a feed pin, and the second antenna unit feed line 152 is connected to the monopole receiving antenna unit 12 through a feed pin.

[0037] Furthermore, the monopole transmitting antenna unit 11 is a metal rod with a diameter of 2 mm and a length of one quarter wavelength of the center operating frequency of 5.8 GHz. Specifically, the length of the monopole transmitting antenna unit 11 is 13 mm. In this embodiment, the input end of the monopole transmitting antenna unit 11 is connected to the RF output port of the radar sensor chip 14 through the antenna unit feeder 15.

[0038] Furthermore, the monopole receiving antenna unit 12 is a metal rod with a diameter of 2 mm and a length of one quarter wavelength of the center operating frequency of 5.8 GHz. Specifically, the length of the monopole receiving antenna unit 12 is 13 mm. In this embodiment, the output end of the monopole receiving antenna unit 12 is connected to the RF input port of the radar sensor chip 14 through the antenna unit feeder 15.

[0039] Furthermore, the microstrip substrate 13 is a FR4 microstrip board, and the size of the microstrip substrate 13 is 20 mm×20 mm. The microstrip substrate 13 is used to install and fix the monopole transmitting antenna unit 11, the monopole receiving antenna unit 12, the surface-mounted radar sensor chip 14, and arrange the antenna unit feed line 15 and the power line and signal line of the radar sensor chip 14.

[0040] In this embodiment, the radar sensor chip 14 is connected to the monopole transmitting antenna unit 11 through the antenna unit feeder 15 and controls the monopole receiving antenna unit 12 to receive signals, so as to detect moving targets.

[0041] Furthermore, the operating frequency band of the transceiver antenna is 5.7 GHz-5.9 GHz, and the center frequency is 5.8 GHz.

[0042] Working principle:

[0043] Transmitting mode: When the radar sensor chip 14 outputs a radio frequency signal, the radio frequency signal is input into the monopole transmitting antenna unit 11 through the first antenna unit feeder 151. According to the end-fire characteristics of the monopole antenna, the radio frequency signal is radiated from the end face of the output end of the monopole transmitting antenna unit 11. The transmitted signal forms omnidirectional radiation in the horizontal direction, which can cover all directions of the surrounding area and realize all-round coverage of the radio frequency signal.

[0044] Receiving mode: The end face of the input end of the monopole receiving antenna unit 12 receives the radio frequency signal reflected from the surrounding area, and sends the received signal to the radar sensor chip 14 through the second antenna unit feeder 152 for signal processing and target detection.

[0045] Figure 2 is a schematic diagram of the beam coverage of the transceiver antenna to the airspace below. The transceiver antenna of the dual end-fire antenna unit provided in this embodiment is installed at the top of the indoor ceiling. Figure 1-2 The normal direction is the ground. Since the monopole transmitting antenna unit 11 and the monopole receiving antenna unit 12 are arranged perpendicular to the microstrip substrate 13, the radiation direction of the received signal is similar to that of the transmitted signal, the gain in the lateral area is higher, and the gain in the normal direction is lower. Therefore, this embodiment can provide a higher receiving gain in the lateral area, thereby enhancing the detection capability of lateral targets.

[0046] Figure 5 It is the elevation radiation pattern of the monopole transmitting antenna unit 11 at the center frequency of 5.8 GHz, where 180° corresponds to the normal direction of the transmitting and receiving antenna, 90-180° and 180-270° are the lateral coverage areas of the transmitting and receiving antenna. It can be seen that the maximum value of its gain coverage is near the lateral angle of 60°. The monopole transmitting antenna unit 11 can achieve the technical characteristics of large lateral gain coverage.

[0047] Figure 6 This is the azimuth plane radiation pattern of the monopole transmitting antenna unit 11 at the center frequency of 5.8 GHz. It can be seen that the azimuth plane gain difference is small, and it has uniform gain coverage in all directions in the azimuth plane.

[0048] Figure 7 It is the elevation radiation pattern of the monopole receiving antenna unit 12 at the center frequency of 5.8 GHz, where 180° corresponds to the normal of the transceiver antenna, 90-180° and 180-270° are the lateral coverage areas of the transceiver antenna. It can be seen that the maximum value of its gain coverage is near the lateral angle of 60°. The monopole receiving antenna unit 12 can also achieve the technical characteristics of large lateral gain coverage.

[0049] Figure 8 This is the azimuth plane radiation pattern of the monopole receiving antenna unit 12 at the center frequency of 5.8 GHz. It can be seen that the azimuth plane gain difference is small, and uniform gain coverage is also achieved in all directions in the azimuth plane.

[0050] Fig. 9 This is the simulation result of the isolation between the port of the monopole transmitting antenna unit 11 and the port of the monopole receiving antenna unit 12 in this embodiment. The isolation can be greater than 20 dB within the working frequency band.

[0051] The above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit the same. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that the technical solutions described in the aforementioned embodiments may still be modified, or some of the technical features may be replaced by equivalents. However, these modifications or replacements do not deviate the essence of the corresponding technical solutions from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. A transceiver antenna with a dual end-fire antenna unit, operating in the frequency band of 5.7 GHz-5.9 GHz, characterized in that: It comprises a monopole transmitting antenna unit (11), a monopole receiving antenna unit (12), a microstrip substrate (13), a radar sensor chip (14), a first antenna unit feed line (151) and a second antenna unit feed line (152); The upper surface of the microstrip substrate (13) is provided with a radar sensor chip (14), a first antenna unit feeder (151) and a second antenna unit feeder (152); the microstrip substrate (13) is provided with a through hole; one end of the first antenna unit feeder (151) is connected to the radio frequency output port of the radar sensor chip (14); the other end of the first antenna unit feeder (151) passes through the through hole and is connected to the input end of the monopole transmitting antenna unit (11); one end of the second antenna unit feeder (152) is connected to the radio frequency input port of the radar sensor chip (14); and the other end of the second antenna unit feeder (152) passes through the through hole and is connected to the output end of the monopole receiving antenna unit (12); A monopole transmitting antenna unit (11) and a monopole receiving antenna unit (12) are vertically arranged on the lower surface of the microstrip substrate (13); the monopole transmitting antenna unit (11) and the monopole receiving antenna unit (12) are parallel to the normal line of the lower surface of the microstrip substrate (13).

2. A transceiver antenna with dual end-fire antenna units according to claim 1, characterized in that: The monopole transmitting antenna unit (11) and the monopole receiving antenna unit (12) are both metal rods, and the length of the rods is one quarter of the wavelength of the central operating frequency.

3. A transceiver antenna with dual end-fire antenna units according to claim 2, characterized in that: The length of the monopole transmitting antenna unit (11) and the monopole receiving antenna unit (12) are both 13 mm, and the diameter is both 2 mm.

4. A transceiver antenna with dual end-fire antenna units according to claim 3, characterized in that: The central operating frequency is 5.8 GHz.

5. The transceiver antenna of the dual end-fire antenna unit according to claim 1, characterized in that: The microstrip substrate (13) is an FR4 microstrip plate, and the size of the microstrip substrate (13) is 20 mm×20 mm.

6. The transceiver antenna of the dual end-fire antenna unit according to claim 1, characterized in that: The first antenna unit feed line (151) is connected to the monopole transmitting antenna unit (11) via a feed pin, and the second antenna unit feed line (152) is connected to the monopole receiving antenna unit (12) via a feed pin.

7. The transceiver antenna of the dual end-fire antenna unit according to claim 1, characterized in that: The working principle of the transceiver antenna is as follows: When the radar sensor chip (14) outputs a radio frequency signal, the radio frequency signal is input into the monopole transmitting antenna unit (11) through the first antenna unit feeder (151). According to the end-fire characteristic of the monopole antenna, the radio frequency signal is radiated from the end face of the output end of the monopole transmitting antenna unit (11). The transmitting signal forms omnidirectional radiation in the horizontal direction, which can cover all directions of the surrounding area, thereby achieving all-round coverage of the radio frequency signal. The end face of the input end of the monopole receiving antenna unit (12) receives radio frequency signals reflected back from the surrounding area, and sends the received signals to the radar sensor chip (14) through the second antenna unit feeder (152) for signal processing and target detection.

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