Broadband wide-beam millimeter wave microstrip array antenna

Abstract

The invention provides a broadband wide-beam millimeter wave micro-strip array antenna, which comprises a dielectric substrate and a metal reflection floor, and is characterized in that the metal reflection floor is arranged on the dielectric substrate in a covering manner; the microstrip array antenna is attached to the metal reflection floor, the microstrip array antenna comprises a feed port, a feeder line and a plurality of antenna branches, the feeder line is horizontally distributed, each antenna branch is of a fan-shaped structure, and the central axis of each antenna branch is perpendicular to the feeder line. According to the invention, the requirements of broadband, wide viewing angle and large-angle high gain can be met at the same time. Meanwhile, the 77.5 GHz frequency band is optimized to meet the working requirements of current and future automobile radar systems, the bandwidth can reach 9.33 GHz, the wide beam characteristic is achieved, in the horizontal plane, the 3dB beam width reaches 118 degrees, in the elevation angle range of + / -75 degrees, the gain is kept above 4.8 dB, the visual field exceeding 150 degrees is achieved, the low sidelobe characteristic is achieved, the pitching surface sidelobe can reach below 19.53 dB, and the wide beam width can reach 118 degrees. And the low-cost R5515 dielectric substrate plate is adopted, so that the overall research and development cost can be remarkably reduced.

Description

Technical Field

[0001] The present invention relates to the field of antenna technology, and in particular to a wide bandwidth beam millimeter wave microstrip array antenna. Background Art

[0002] Compared with traditional antennas, microstrip antennas are small, light, low-profile, and easy to conform to, so microstrip array antennas are widely used in communications, radar, and other fields. When the antenna installation space is limited and the carrier is miniaturized, the small size, low profile, and easy conformity of microstrip antennas just meet the needs of these application scenarios.

[0003] However, with the rapid development of autonomous driving and advanced driver assistance system (ADAS) technologies, the requirements for automotive radar systems are increasing, especially corner radar systems, which need to achieve high-precision target detection in complex driving environments. Traditional microstrip antennas often find it difficult to simultaneously meet the requirements of broadband, wide viewing angle, and high gain at large angles, especially in high frequency bands such as 77.5 GHz, which limits the performance of automotive radar systems. Therefore, it is particularly important to develop a microstrip array antenna that can operate at 77.5 GHz with high gain at large angles, wide bandwidth, and a wide field of view (FOV). Summary of the invention

[0004] In view of this, the present invention provides a wide bandwidth beam millimeter wave microstrip array antenna, which can simultaneously meet the requirements of broadband, wide viewing angle and high gain at a large angle.

[0005] An embodiment of the present invention provides a wide bandwidth beam millimeter wave microstrip array antenna, comprising:

[0006] dielectric substrate;

[0007] A metal reflective floor, the metal reflective floor is covered and arranged on the dielectric substrate;

[0008] A microstrip array antenna, wherein the microstrip array antenna is attached to the metal reflective floor, and the microstrip array antenna comprises a feeding port, a feed line and a plurality of antenna branches, wherein the feed line is horizontally distributed, each antenna branch is a fan-shaped structure, and the central axis of each antenna branch is perpendicular to the feed line.

[0009] Furthermore, the matching structure of the feeding port is Y-shaped, and the feed lines are distributed in parallel along two sides of the feeding port.

[0010] Furthermore, the matching structure of the feeding port is funnel-shaped, and the feeding lines are distributed in parallel along two sides of the feeding port.

[0011] Furthermore, the matching structure of the feeding port is S-shaped, and the feed lines are distributed in parallel along two sides of the feeding port.

[0012] Furthermore, the distance between the edge of each antenna branch and the feeder line changes gradually in sequence.

[0013] Furthermore, each antenna branch is distributed at intervals along the feeder line.

[0014] Furthermore, the feeding port is 50 ohms.

[0015] Furthermore, the dielectric substrate is a Panasonic R5515 dielectric substrate plate.

[0016] Furthermore, the bandwidth range of the wide bandwidth beam millimeter wave microstrip array antenna is 74.8 GHz to 84.13 GHz.

[0017] Furthermore, in the horizontal plane, the 3dB beamwidth reaches 118°.

[0018] The technical solution provided by the present invention is to set the feeder of the wide bandwidth beam millimeter wave microstrip array antenna to be horizontally distributed, and each antenna branch is set to a fan-shaped structure, and the central axis of each antenna branch is perpendicular to the feeder. It can simultaneously meet the requirements of broadband, wide viewing angle and high gain at a large angle. At the same time, the technical solution provided by the present invention is optimized for the 77.5GHz frequency band to match the working requirements of current and future automotive radar systems. It has broadband characteristics, with a bandwidth of up to 9.33GHz, which can cover 74.8GHz to 84.13GHz, ensuring stable performance in a wider frequency range and enhancing the tracking ability of objects at different speeds; it has wide beam characteristics: in the horizontal plane, the 3dB beam width reaches 118°, which is wider than conventional millimeter wave antennas. Compared with ordinary comb antennas, the horizontal beam width can be increased by more than 56%, and the longitudinal antenna size can be reduced by more than 50%. It ensures high-sensitivity detection within a wide-angle range and effectively covers the area around the vehicle; at the same time, the gain at a large angle is high: within the elevation angle range of ±75°, the gain is maintained at more than 4.8dB, which improves the effective distance at a large angle; it has a wide field of view (FOV): through innovative antenna structure design, a field of view of more than 150° is achieved, which significantly improves the automotive radar's perception of the surrounding environment; it has low sidelobe characteristics: the wide-bandwidth beam millimeter-wave array antenna developed by the present invention has a sidelobe of less than -19.53dB on the elevation plane; it has low-cost characteristics: the use of low-cost Panasonic R5515 dielectric substrate panels can significantly reduce the overall R&D cost compared to Rogers panels. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] Figure 1 is a schematic diagram of a wide bandwidth beam millimeter wave microstrip array antenna provided by an embodiment of the present invention;

[0020] Figure 2 is a return loss diagram of a wide bandwidth beam millimeter wave microstrip array antenna in an embodiment of the present invention;

[0021] Figure 3 It is a gain pattern curve of the microstrip array antenna provided by an embodiment of the present invention. DETAILED DESCRIPTION

[0022] In order to make the purpose, technical solution and advantages of the present invention clearer, the present invention will be further described in detail below in conjunction with the accompanying drawings. Obviously, the described embodiments are only part of the embodiments of the present invention, rather than all 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.

[0023] Embodiment 1

[0024] See also Figure 1 , Figure 1 It is a schematic diagram of a wide bandwidth beam millimeter wave microstrip array antenna provided by an embodiment of the present invention. The wide bandwidth beam millimeter wave microstrip array antenna provided by an embodiment of the present invention can be used in an automotive corner radar system, or can be used in other scenarios that require broadband, wide viewing angle, and high gain at a large angle. The wide bandwidth beam millimeter wave microstrip array antenna includes a dielectric substrate (not shown), a metal reflective floor (not shown) covering the bottom surface of the dielectric substrate, and a microstrip array antenna attached to the top surface of the dielectric substrate. A low-cost Panasonic R5515 dielectric substrate plate is used. A feeding port is provided on the microstrip array antenna, and it radiates outward as a complete radiator.

[0025] The feed line is horizontally distributed, the central axis of all antenna branches is perpendicular to the feed line, and the antenna branches are all wide fan-shaped structures. The feed port is a 50 ohm microstrip feed, and the branches are periodically staggered along both sides of the microstrip line.

[0026] Among them, the longitudinal distance from the antenna branch to the microstrip line presents a gradual change, which makes it easy to achieve lower sidelobe weighting.

[0027] In some embodiments, the matching structure of the feeding port is in a Y-shape, a funnel shape, or an S-shape, and the feed lines are distributed in parallel along two sides of the feeding port.

[0028] Figure 2The return loss of the microstrip array antenna provided by the embodiment of the present invention is shown, where the horizontal axis represents the frequency and the vertical axis represents the return loss. Since the microstrip array antenna designed in this embodiment has strong structural continuity and small reflected energy, it can be seen from the figure that the return loss at 77.5GHz is below -25dB. The antenna has a wide bandwidth, with a -10dB impedance bandwidth of 74.8-84.13GHz and an absolute bandwidth of up to 9.33GHz.

[0029] Figure 3 The gain radiation pattern curve of the microstrip array antenna provided by an embodiment of the present invention is shown. The half-power beam width of the antenna in azimuth plane is 118°, which has the characteristics of a wide-beam antenna. The beam width in elevation plane is 19.48°, and the sidelobe level is lower than -19.53dB, which has good low sidelobe characteristics.

[0030] With the same number of array elements, compared with ordinary comb antennas, the horizontal beam width can be increased by more than 56%, and the gain of ±75° is improved compared with traditional comb antennas. The antenna design fully considers the special needs of automotive applications and achieves a high degree of integration and miniaturization. The longitudinal antenna size can be reduced by more than 50%.

[0031] Therefore, the technical solution provided by the present invention is to set the feeder of the wide bandwidth beam millimeter wave microstrip array antenna to be horizontally distributed, each antenna branch is set to a fan-shaped structure, and the central axis of each antenna branch is perpendicular to the feeder. It can simultaneously meet the requirements of broadband, wide viewing angle and high gain at a large angle. At the same time, the technical solution provided by the present invention is optimized for the 77.5GHz frequency band to match the working requirements of current and future automotive radar systems. It has broadband characteristics, with a bandwidth of up to 9.33GHz, which can cover 74.8GHz to 84.13GHz, ensuring stable performance in a wider frequency range and enhancing the tracking ability of objects at different speeds; it has wide beam characteristics: in the horizontal plane, the 3dB beam width reaches 118°, which is wider than conventional millimeter wave antennas. Compared with ordinary comb antennas, the horizontal beam width can be increased by more than 56%, and the longitudinal antenna size can be reduced by more than 50%. It ensures high-sensitivity detection within a wide-angle range and effectively covers the area around the vehicle; at the same time, the gain at a large angle is high: within the elevation angle range of ±75°, the gain is maintained at more than 4.8dB, which improves the effective distance at a large angle; it has a wide field of view (FOV): through innovative antenna structure design, a field of view of more than 150° is achieved, which significantly improves the automotive radar's perception of the surrounding environment; it has low sidelobe characteristics: the wide-bandwidth beam millimeter-wave array antenna developed by the present invention has a sidelobe of less than -19.53dB on the elevation plane; it has low-cost characteristics: the use of low-cost Panasonic R5515 dielectric substrate panels can significantly reduce the overall R&D cost compared to Rogers panels.

[0032] The above specific implementations do not constitute a limitation on the protection scope of the present invention. It should be understood by those skilled in the art that various modifications, combinations, sub-combinations and substitutions can be made according to design requirements and other factors. 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 present invention.

Claims

1. A wide bandwidth beam millimeter wave microstrip array antenna, characterized in that: include: dielectric substrate; A metal reflective floor, the metal reflective floor is covered and arranged on the dielectric substrate; A microstrip array antenna, wherein the microstrip array antenna is attached to the metal reflective floor, and the microstrip array antenna comprises a feeding port, a feed line and a plurality of antenna branches, wherein the feed line is horizontally distributed, each antenna branch is a fan-shaped structure, and the central axis of each antenna branch is perpendicular to the feed line.

2. The wide bandwidth beam millimeter wave microstrip array antenna according to claim 1, characterized in that: The matching structure of the feeding port is Y-shaped, and the feed lines are distributed in parallel along two sides of the feeding port.

3. The wide bandwidth beam millimeter wave microstrip array antenna according to claim 1, characterized in that: The matching structure of the feeding port is funnel-shaped, and the feeding lines are distributed in parallel along two sides of the feeding port.

4. The wide bandwidth beam millimeter wave microstrip array antenna according to claim 1, characterized in that: The matching structure of the feeding port is S-shaped, and the feed lines are distributed in parallel along two sides of the feeding port.

5. The wide bandwidth beam millimeter wave microstrip array antenna according to claim 1, characterized in that: The distance between the edge of each antenna branch and the feeder line changes gradually.

6. The wide bandwidth beam millimeter wave microstrip array antenna according to claim 1, characterized in that: Each antenna branch is distributed at intervals along the feed line.

7. The wide bandwidth beam millimeter wave microstrip array antenna according to any one of claims 1 to 6, characterized in that: The impedance matched to the feeding port is 50 ohms.

8. The wide bandwidth beam millimeter wave microstrip array antenna according to claim 7, characterized in that: The dielectric substrate is a Panasonic R5515 dielectric substrate plate.

9. The wide bandwidth beam millimeter wave microstrip array antenna according to claim 7, characterized in that: The bandwidth range of the wide bandwidth beam millimeter wave microstrip array antenna is 74.8 GHz to 84.13 GHz.

10. The wide bandwidth beam millimeter wave microstrip array antenna according to claim 7, characterized in that: In the horizontal plane, the 3dB beamwidth reaches 118°.

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