A transceiving antenna for a dual end-fire antenna element

Abstract

This invention discloses a transceiver antenna with a dual-end-fire antenna element, belonging to the field of antenna technology. It addresses the problems of significant differences in target detection capabilities across different azimuth angles and weak lateral target detection capabilities in 5.8GHz radar sensor antenna designs. The invention employs two end-fire monopole antenna elements as the transceiver ends. These antenna elements possess omnidirectional radiation characteristics, resulting in consistent gain coverage for both the transmitting and receiving antennas across different azimuth angles, effectively improving the consistency of target detection capabilities across these angles. Furthermore, the end-fire monopole antennas exhibit lower gain in the normal direction of the radar sensor module, with the lateral direction being the direction of maximum radiation gain, significantly enhancing lateral target detection capabilities and thus increasing the target detection range to meet the requirements for omnidirectional target detection.

Description

Technical Field

[0001] This invention belongs to the field of antenna technology and relates to a transceiver antenna for a dual-ended emitting antenna element. Background Technology

[0002] Radar sensors consist of transmitting and receiving antennas, capable of emitting and receiving electromagnetic wave signals. They determine the presence of moving objects by detecting the frequency difference between the transmitted and received signals using the Doppler principle, thus achieving target detection. Radar sensors have multiple operating frequency bands, including 5.8GHz, 24GHz, and 77GHz, and are applied in scenarios where people are present or moving. Among these, 5.8GHz radar sensors are primarily used in smart lighting, and are widely used in lighting products such as induction bulbs and T8 tubes, showing broad application prospects in smart homes, the Internet of Things (IoT), and security. Currently, commonly used 5.8GHz radar sensors often employ dual-polarized microstrip patch antennas, containing two orthogonal polarization ports corresponding to the radar sensor's receiving and transmitting antenna ports, respectively. The transmission and reception of the radar sensor are achieved through an orthogonal dual-polarized antenna, while the orthogonal polarization ensures isolation between the transmitting and receiving ports, enabling the function of moving target detection. Figure 1 This illustrates the beam coverage of a dual-polarized microstrip antenna element in the current technology. A 5.8GHz radar sensor based on a dual-polarized microstrip patch antenna has the following technical drawbacks:

[0003] (1) To ensure isolation between the transmitting and receiving ports, the polarizations of the receiving and transmitting antennas are orthogonal at 90°. In the angular region parallel to the polarization of the transmitting antenna, the transmitting antenna transmits its dominant polarization component, resulting in a strong transmitted signal. However, the receiving antenna can only receive the signal through its lower-amplitude cross-polarization component, leading to a relatively weak received signal. In the angular region parallel to the polarization of the receiving antenna, the transmitting antenna transmits its orthogonal cross-polarization component, resulting in a very weak transmitted signal. Although the receiving antenna receives the signal through its stronger dominant polarization component, the received signal strength is still relatively weak.

[0004] (2) A microstrip antenna is a planar side-fired antenna, and its radiation gain is strongest at its normal direction. For radar sensor modules, the detection range is longest at the direction perpendicular to the module's normal. However, 5.8GHz radar sensors are used in applications such as smart lighting, where the radar sensor module is usually placed on the ceiling or other top positions. Moving targets typically approach the normal direction from the side, making lateral target detection capability more critical to the overall detection capability of the radar sensor. Therefore, the current 5.8GHz radar sensor antenna design suffers from problems such as large differences in angular target detection capability at different azimuths and weak lateral target detection capability. Summary of the Invention

[0005] The technical solution of this invention is used to solve the problems of large differences in the detection capability of targets in different angular domains and weak detection capability of lateral targets in the design of 5.8GHz radar sensor antennas.

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

[0007] A transceiver antenna with a dual-ended emitting antenna element, operating in the frequency band of 5.7GHz-5.9GHz, includes a monopole transmitting antenna element, a monopole receiving antenna element, a microstrip substrate, a radar sensor chip, a first antenna element feed line, and a second antenna element feed line.

[0008] The upper surface of the microstrip substrate is provided with a radar sensor chip, a first antenna unit feed line, and a second antenna unit feed line. The microstrip substrate has through holes. One end of the first antenna unit feed line is connected to the radio frequency output port of the radar sensor chip, and the other end of the first antenna unit feed line passes through the through hole and is connected to the input terminal of the monopole transmitting antenna unit. One end of the second antenna unit feed line is connected to the radio frequency input port of the radar sensor chip, and the other end of the second antenna unit feed line passes through the through hole and is connected to the output terminal of the monopole receiving antenna unit.

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

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

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

[0012] Furthermore, the center's operating frequency is 5.8 GHz.

[0013] Furthermore, the microstrip substrate is an FR4 microstrip material with a size of 20mm × 20mm.

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

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

[0016] When the radar sensor chip outputs a radio frequency (RF) signal, the RF signal is input to the monopole transmitting antenna unit through the feed line of the first antenna unit. According to the end-fire characteristic of the monopole antenna, the RF signal is radiated from the end face of the output end of the monopole transmitting antenna unit. The transmitted signal forms omnidirectional radiation in the horizontal direction, which can cover all directions around it and achieve all-round coverage of the RF signal.

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

[0018] The advantages of this invention are:

[0019] This invention employs two end-fired monopole antenna elements as the transmitting and receiving ends of the transceiver antenna. These antenna elements possess omnidirectional radiation characteristics, ensuring consistent gain coverage between the transmitting and receiving antennas in different azimuth angular domains. This effectively improves the consistency of target detection capabilities of the radar sensor across different azimuth angular domains. Furthermore, the end-fired monopole antennas used in this invention have lower gain in the normal direction of the radar sensor module, with the lateral direction exhibiting the greatest radiation gain. This significantly enhances lateral target detection capabilities, thereby increasing the target detection range and meeting the requirements for omnidirectional target detection. Attached Figure Description

[0020] Figure 1 This is a schematic diagram of the beam coverage of a dual-polarized microstrip antenna element under existing technology;

[0021] Figure 2 This is a schematic diagram of the beam coverage of the dual-ended firing antenna unit according to Embodiment 1 of the present invention;

[0022] Figure 3 This is a structural diagram of the transceiver antenna of a dual-ended emitting antenna unit according to Embodiment 1 of the present invention;

[0023] Figure 4 This is a front view of the transceiver antenna of a dual-ended emitting antenna unit according to Embodiment 1 of the present invention;

[0024] Figure 5 This is the radiation pattern of the monopole transmitting antenna element of Embodiment 1 of the present invention at the elevation plane with a center frequency of 5.8 GHz;

[0025] Figure 6 This is the azimuth radiation pattern of the monopole transmitting antenna element of Embodiment 1 of the present invention at a center frequency of 5.8 GHz;

[0026] Figure 7 This is the radiation pattern of the monopole receiving antenna element of Embodiment 1 of the present invention at the elevation plane with a center frequency of 5.8 GHz;

[0027] Figure 8 This is the azimuth radiation pattern of the monopole receiving antenna element of Embodiment 1 of the present invention at a center frequency of 5.8 GHz.

[0028] Figure 9 This is a simulation curve of the isolation between the port of the monopole transmitting antenna element and the port of the monopole receiving antenna element in Embodiment 1 of the present invention;

[0029] Reference numerals: 11, Monopole transmitting antenna element; 12, Monopole receiving antenna element; 13, Microstrip substrate; 14, Radar sensor chip; 151, First antenna element feed line; 152, Second antenna element feed line. Detailed Implementation

[0030] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions of the embodiments of the present invention will be clearly and completely described below in conjunction with the embodiments of the present invention. Obviously, the described embodiments are only some embodiments of the present invention, not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0031] The technical solution of the present invention will be further described below with reference to the accompanying drawings and specific embodiments:

[0032] Example 1

[0033] like Figure 3-4 As shown, specifically, a dual-ended transmitting antenna unit 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 feed line 151, and a second antenna unit feed line 152. The microstrip substrate 13 has through holes. One end of the first antenna unit feed line 151 is connected to the radio frequency output port of the radar sensor chip 14, and the other end of the first antenna unit feed line 151 passes through the through hole and is connected to the input terminal of the monopole transmitting antenna unit 11. One end of the second antenna unit feed line 152 is connected to the radio frequency input port of the radar sensor chip 14, and the other end of the second antenna unit feed line 152 passes through the through hole and is connected to the output terminal of the monopole receiving antenna unit 12.

[0035] The lower surface of the microstrip substrate 13 is vertically provided with a monopole transmitting antenna unit 11 and a monopole receiving antenna unit 12; the monopole transmitting antenna unit 11 and the monopole receiving antenna unit 12 are parallel to the normal to 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 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.

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

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

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

[0040] In this embodiment, the radar sensor chip 14 is connected to and controls the monopole transmitting antenna unit 11 to transmit signals and the monopole receiving antenna unit 12 to receive signals via the antenna unit feed line 15, for detecting moving targets.

[0041] Furthermore, the transceiver antenna operates in the frequency band of 5.7GHz-5.9GHz, with a center frequency of 5.8GHz.

[0042] Working principle:

[0043] Transmission mode: When the radar sensor chip 14 outputs a radio frequency signal, the radio frequency signal is input to the monopole transmitting antenna unit 11 through the first antenna unit feed line 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 transmitted signal forms omnidirectional radiation in the horizontal direction, which can cover all directions around and realize the all-round coverage of the radio frequency signal.

[0044] Reception mode: The end face of the input end of the monopole receiving antenna unit 12 receives the 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 feed line 152 for signal processing and target detection.

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

[0046] Figure 5 The image shows the radiation pattern of the monopole transmitting antenna element 11 in the elevation plane at a center frequency of 5.8 GHz. 180° corresponds to the normal of the transmitting and receiving antenna, and 90-180° and 180-270° are the lateral coverage areas of the transmitting and receiving antenna. It can be seen that the maximum gain coverage is near the lateral 60° angle. The monopole transmitting antenna element 11 can achieve the technical feature of large lateral gain coverage.

[0047] Figure 6 The image shows the azimuth radiation pattern of the monopole transmitting antenna element 11 at a center frequency of 5.8 GHz. It can be seen that its azimuth gain difference is small and it has uniform gain coverage in the omnidirectional direction of the azimuth plane.

[0048] Figure 7 The image shows the radiation pattern of the monopole receiving antenna element 12 in the elevation plane at a center frequency of 5.8 GHz. 180° corresponds to the normal of the transmitting and receiving antenna, and 90-180° and 180-270° are the lateral coverage areas of the transmitting and receiving antenna. It can be seen that the maximum gain coverage is near the lateral 60° angle. The monopole receiving antenna element 12 can also achieve the technical feature of large lateral gain coverage.

[0049] Figure 8 The image shows the azimuth radiation pattern of the monopole receiving antenna element 12 at a center frequency of 5.8 GHz. It can be seen that the azimuth gain difference is small, and uniform gain coverage is achieved in the omnidirectional direction of the azimuth plane.

[0050] Figure 9 The simulation results of the isolation between port 11 of the monopole transmitting antenna unit and port 12 of the monopole receiving antenna unit in this embodiment show that the isolation can be greater than 20dB within the operating frequency band.

[0051] The above embodiments are only used to illustrate the technical solutions of the present invention, and are not intended to limit it. Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features. Such modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. A transceiver antenna for a dual-ended RF antenna element, operating in the frequency band of 5.7GHz-5.9GHz, characterized in that, It includes 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 feed line (151), and a second antenna unit feed line (152). The microstrip substrate (13) has through holes. One end of the first antenna unit feed line (151) is connected to the radio frequency output port of the radar sensor chip (14), and the other end of the first antenna unit feed line (151) passes through the through hole and is connected to the input terminal of the monopole transmitting antenna unit (11). One end of the second antenna unit feed line (152) is connected to the radio frequency input port of the radar sensor chip (14), and the other end of the second antenna unit feed line (152) passes through the through hole and is connected to the output terminal of the monopole receiving antenna unit (12). The lower surface of the microstrip substrate (13) is vertically provided with a monopole transmitting antenna unit (11) and a monopole receiving antenna unit (12); the monopole transmitting antenna unit (11) and the monopole receiving antenna unit (12) are parallel to the normal of the lower surface of the microstrip substrate (13), and both the monopole transmitting antenna unit (11) and the monopole receiving antenna unit (12) are metal rods.

2. The transceiver antenna of a dual-ended firing antenna element according to claim 1, characterized in that, The lengths of both the monopole transmitting antenna unit (11) and the monopole receiving antenna unit (12) are one-quarter of the wavelength of the center operating frequency.

3. The transceiver antenna of a dual-ended firing antenna element according to claim 2, characterized in that, The length of both the monopole transmitting antenna unit (11) and the monopole receiving antenna unit (12) is 13mm and the diameter is 2mm.

4. The transceiver antenna of a dual-ended firing antenna element according to claim 3, characterized in that, The center operates at a frequency of 5.8 GHz.

5. The transceiver antenna of a dual-ended emitting antenna element according to claim 1, characterized in that, The microstrip substrate (13) is an FR4 microstrip material, and the size of the microstrip substrate (13) is 20mm×20mm.

6. The transceiver antenna of a dual-ended RF antenna element 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 a dual-ended firing antenna element 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 to the monopole transmitting antenna unit (11) through the first antenna unit feed line (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 transmitted signal forms omnidirectional radiation in the horizontal direction, which can cover all directions around and realize the all-round coverage of the radio frequency signal. The end face of the input end of the monopole receiving antenna unit (12) receives the radio frequency signal reflected back from the surrounding area, and sends the received signal to the radar sensor chip (14) through the second antenna unit feed line (152) for signal processing and target detection.

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