Array horn antenna system based on 77GHz millimeter wave radar

Abstract

The utility model relates to an array horn antenna transmit-receive system based on a 77GHz millimeter wave radar, and belongs to the technical field of antennas. The antenna comprises a transmitting antenna and three receiving antennas which are waveguide-coupled horn array antennas, each horn array antenna comprises a three-layer structure, the bottom layer is a first feed structure layer of a bent waveguide structure, and the middle layer is a second feed structure layer of an array slot structure; and the upper layer is a horn antenna layer with a horn array structure. The horn antenna is composed of M array elements, and the M array elements are symmetrically distributed about the center feed position. Therefore, the array horn antenna system based on the 77GHz millimeter wave radar is provided, and the array horn antenna system has the advantages that waveguide feeding is achieved, wide wave beams can be guaranteed, mutual coupling between the antennas is small, the consistency between the antennas is good, the loss is small, and the gain is high. The array horn antenna system can be applied to a vehicle-mounted millimeter wave angle radar, and middle and long distance target detection is realized.

Description

Technical Field

[0001] The utility model relates to the field of antenna technology, in particular to the field of millimeter wave radar technology, and more particularly to an array horn antenna system based on a 77GHz millimeter wave radar. Background Art

[0002] As driver assistance technology matures, market demand for millimeter-wave corner radar is increasing. Currently, most 77GHz corner radar products on the market use microstrip antennas or substrate-integrated waveguide antennas. Microstrip antennas generally have a narrow horizontal beamwidth, making it difficult to cover an angular range of ±75 degrees. Even if they manage to do so, there is a high rate of false alarms or missed alarms. Substrate-integrated waveguide antennas have a wider horizontal beamwidth, but their surface wave mutual coupling is relatively large, resulting in poor antenna beam consistency.

[0003] Therefore, how to provide a millimeter-wave radar antenna that ensures a wide beam while having small inter-antenna coupling has become an urgent problem to be solved in this field. Utility Model Content

[0004] The purpose of the present utility model is to overcome the shortcomings of the above-mentioned prior art and provide a waveguide-fed array horn antenna system based on 77GHz millimeter wave radar, which can ensure a wide beam while having smaller mutual coupling between antennas and better consistency between antennas.

[0005] In order to achieve the above objectives, the array horn antenna system based on 77GHz millimeter wave radar of the present invention has the following structure:

[0006] The array horn antenna transceiver system based on 77GHz millimeter wave radar includes a transmitting antenna Tx1 and three receiving antennas Rx1, Rx2, and Rx3. The transmitting antenna Tx1 and the receiving antennas Rx1, Rx2, and Rx3 all adopt waveguide-coupled horn array antennas and are connected to the 77GHz millimeter wave radar chip through a microstrip-to-waveguide structure. The horn array antenna includes a three-layer structure. The bottom layer is a first feeding structure layer of a curved waveguide structure, which feeds electromagnetic waves to the bottom feeding position at the center of the bottom of the horn array antenna; the middle layer is a second feeding structure layer, which is an array slot structure symmetrically distributed about the bottom feeding position, and transfers the electromagnetic waves fed by the curved waveguide structure of the bottom layer to the upper layer; the upper layer is a horn antenna layer of a horn array structure, which radiates the electromagnetic waves received from the second feeding structure layer into free space.

[0007] In the array horn antenna transceiver system based on 77GHz millimeter wave radar, the transmitting antenna Tx1 and the receiving antennas Rx1, Rx2, and Rx3 are all linear arrays, the number of array elements is M, M is an even number, and the array elements are symmetrical with the bottom feeding position as the center. The first feeding structure layer and the second feeding structure layer form a double-layer feeding structure, and a one-to-two power divider is formed through a shared rectangular gap. The feeding coupling array elements between the first feeding structure layer and the second feeding structure layer are symmetrically distributed.

[0008] In the array horn antenna transceiver system based on 77GHz millimeter wave radar, the bottom curved waveguide structure is matched with the microstrip waveguide structure through the rectangular gap.

[0009] In the array horn antenna transceiver system based on 77GHz millimeter wave radar, the lateral spacing between the receiving antennas Rx1, Rx2, and Rx3 is 0, the longitudinal spacing between the receiving antenna Rx1 and the receiving antenna Rx2 is 1.5 wavelengths, and the longitudinal spacing between the receiving antenna Rx2 and the receiving antenna Rx3 is 2 wavelengths; the lateral spacing between the receiving antenna Rx3 and the transmitting antenna Tx1 is 9mm, and the longitudinal spacing is 2 wavelengths.

[0010] In the array horn antenna transceiver system based on 77GHz millimeter wave radar, the horn array structure is a linear horn radiation structure, which shares a horn mouth, and the waveguide transmission parts of the horn antenna are independent.

[0011] In the array horn antenna transceiver system based on 77GHz millimeter wave radar, conductive glue is provided between the three-layer structure, and the curved waveguide structure is made of aluminum; the materials of the array slot structure and the linear horn radiation structure are both made of aluminum or copper and filled with air.

[0012] The utility model uses an array horn antenna transceiver system based on a 77GHz millimeter-wave radar, including one transmitting antenna and three receiving antennas, all of which use waveguide-coupled horn array antennas. The horn array antenna comprises a three-layer structure: a first feeding structure layer of a curved waveguide structure at the bottom layer, a second feeding structure layer in the middle layer, and an array slot structure symmetrically distributed about the bottom layer's feeding position. The second feeding structure layer transfers the electromagnetic waves fed by the curved waveguide structure of the bottom layer to the upper layer; the upper layer is a horn antenna layer of a horn array structure. This provides a waveguide-fed array horn antenna system based on a 77GHz millimeter-wave radar that can ensure a wide beam while having minimal mutual coupling between antennas and good consistency between antennas. Furthermore, this array horn antenna system can be applied to vehicle-mounted millimeter-wave corner radars to achieve medium- and long-range target detection. BRIEF DESCRIPTION OF THE DRAWINGS

[0013] Figure 1 This is a top view of the bottom feed structure of the array horn antenna system based on 77GHz millimeter wave radar of the utility model;

[0014] Figure 2 This is a top view of the middle-layer feed structure of the array horn antenna system based on 77GHz millimeter wave radar of the utility model;

[0015] Figure 3 This is a top view of the upper horn array of the array horn antenna system based on 77GHz millimeter wave radar of the utility model;

[0016] Figure 4 This is an overall front view of the array horn antenna system based on 77GHz millimeter wave radar of the present invention;

[0017] Figure 5 This is a waveform diagram of a 77GHz millimeter wave radar using the array horn antenna system of the present invention;

[0018] Figure 6 The figure is a waveform diagram of a 77 GHz millimeter wave radar using the array horn antenna system of the present invention. DETAILED DESCRIPTION

[0019] In order to more clearly understand the technical content of the present invention, the following embodiments are given to explain in detail.

[0020] like Figure 1 、 Figure 2 、 Figure 3 、 Figure 4 Figure 2 shows a schematic diagram of the structure of the array horn antenna system for 77GHz millimeter-wave radar in this utility model. The antenna system consists of a three-layer structure, including two feeding layers and a radiating layer, connected in the middle by conductive adhesive. The first feeding structure layer (bottom layer) 1 and the second feeding structure layer (middle layer) 2 form a one-to-two power splitter through a shared rectangular slot 4. The second feeding structure layer then transmits the electromagnetic waves to the bottom of each horn antenna in the radiating layer (upper layer) 3 for feeding.

[0021] The millimeter-wave radar array horn antenna described in this utility model includes one transmitting antenna and three receiving antennas. The horizontal spacing between the receiving antennas is 0 mm, the vertical spacing between receiving antennas Rx1 and Rx2 is 5.88 mm, and the spacing between receiving antennas Rx2 and Rx3 is 7.84 mm. The horizontal spacing between receiving antenna Rx3 and transmitting antenna Tx1 is 9 mm, and the vertical spacing is 7.84 mm.

[0022] In a further embodiment, the transmitting antenna Tx1 and the receiving antennas Rx1, Rx3, Rx4 are all composed of a curved waveguide structure, which is used to feed electromagnetic wave to the bottom of the horn antenna.

[0023] In a further embodiment, the transmitting antenna and the receiving antennas are both composed of a 1x8 linear array structure, which is axially symmetrically distributed with respect to the rectangular slot 4 shared by the first feeding structure layer 1 and the second feeding structure layer 2.

[0024] In a further embodiment, the material of the millimeter wave radar array horn antenna is composed of aluminum or copper structure.

[0025] In a further embodiment, in order to match the microstrip-to-waveguide structure, another rectangular slot 5 is opened at the bottom of the curved waveguide of the first feeding structure layer 1, as shown in Figure 1 The distance wg1_d (as shown in Figure 1 ) between the rectangular slot 5 and the waveguide wall can adjust the impedance matching of the structure.

[0026] In a further embodiment, the horn antenna radiation structure is composed of 8 rectangular waveguide openings and one horn opening, and the size of each horn opening is equal. In order to make each array element have the same phase, the spacing between each horn opening is slightly different.

[0027] In this embodiment, the specific parameters of the antenna are shown in Table 1. The parameters of the second feeding structure layer 2 of the transmitting antenna and the receiving antenna and the parameters of the radiation horn structure are the same, and only the parameters of the first feeding structure layer 1 are slightly different.

[0028]

[0029]

[0030] Table 1 Specific parameter values of the microstrip antenna array in this embodiment

[0031] In this embodiment, all the structural units are composed of aluminum three-dimensional geometric structures, which saves the high-frequency material on the ordinary millimeter wave radar antenna. The machining or 3D printing method can be used for early antenna verification, which reduces the development cost. Figure 5 and Figure 6 As shown in the figures, the pattern performance of the radar system is as follows:

[0032] The elevation plane gain of the receiving antenna Rx1 is >15.6dB, the sidelobe level is <-17dB, and the 3dB beam width is 8.95 degrees; the horizontal plane gain is >16.2dB, and the 3dB beam width is 72 degrees.

[0033] The elevation gain of the receiving antenna Rx2 is greater than 14.78 dB, the sidelobe level is less than -16.9 dB, and the 3dB beamwidth is 8.9 degrees. The horizontal gain is greater than 16.3 dB, and the 3dB beamwidth is 67 degrees.

[0034] The elevation gain of the receiving antenna Rx3 is greater than 14.8 dB, the sidelobe level is less than -17 dB, and the 3 dB beamwidth is 8.9 degrees. The horizontal gain is greater than 15.81 dB, and the 3 dB beamwidth is 105 degrees.

[0035] The elevation gain of the transmitting antenna Tx1 is greater than 15 dB, the sidelobe level is less than -16 dB, and the 3 dB beamwidth is 9 degrees. The horizontal gain is greater than 15.44 dB, and the 3 dB beamwidth is 131 degrees.

[0036] The millimeter-wave radar horn array antenna transceiver system has high directional gain, wide horizontal beam, and good consistency. Combined with the microstrip-to-waveguide coupling structure, it can be used for detecting targets at medium and long distances in vehicle-mounted millimeter-wave angle radars.

[0037] The utility model uses an array horn antenna transceiver system based on a 77GHz millimeter-wave radar, including one transmitting antenna and three receiving antennas, all of which use waveguide-coupled horn array antennas. The horn array antenna comprises a three-layer structure: a first feeding structure layer of a curved waveguide structure at the bottom layer, a second feeding structure layer in the middle layer, and an array slot structure symmetrically distributed about the bottom layer's feeding position. The second feeding structure layer transfers the electromagnetic waves fed by the curved waveguide structure of the bottom layer to the upper layer; the upper layer is a horn antenna layer of a horn array structure. This provides a waveguide-fed array horn antenna system based on a 77GHz millimeter-wave radar that can ensure a wide beam while having minimal mutual coupling between antennas and good consistency between antennas. Furthermore, this array horn antenna system can be applied to vehicle-mounted millimeter-wave corner radars to achieve medium- and long-range target detection.

[0038] In this specification, the present invention has been described with reference to specific embodiments thereof. However, it will be apparent that various modifications and variations may be made without departing from the spirit and scope of the present invention. Accordingly, the specification and drawings are to be regarded as illustrative rather than restrictive.

Claims

1. An array horn antenna transceiver system based on 77GHz millimeter wave radar, characterized in that: It includes a transmitting antenna Tx1 and three receiving antennas Rx1, Rx2, and Rx3. The transmitting antenna Tx1 and the receiving antennas Rx1, Rx2, and Rx3 all use waveguide-coupled horn array antennas and are connected to the 77GHz millimeter wave radar chip through a microstrip-to-waveguide structure. The horn array antenna includes a three-layer structure, the bottom layer of which is the first feeding structure layer of the curved waveguide structure, which feeds electromagnetic waves to the bottom feeding position at the center of the bottom of the horn array antenna. The middle layer is the second feeding structure layer, which is an array slot structure symmetrically distributed about the bottom layer feeding position, and transfers the electromagnetic waves fed by the curved waveguide structure of the bottom layer to the upper layer; the upper layer is a horn antenna layer of a horn array structure, which radiates the electromagnetic waves received from the second feeding structure layer into the free space.

2. The array horn antenna transceiver system based on 77GHz millimeter wave radar according to claim 1 is characterized in that: The transmitting antenna Tx1 and the receiving antennas Rx1, Rx2, and Rx3 are all linear arrays, the number of array elements is M, M is an even number, the array elements are symmetrical with the bottom feeding position as the center, the first feeding structure layer and the second feeding structure layer form a double-layer feeding structure, and a one-to-two power divider is formed through a shared rectangular gap, and the feeding coupling array elements between the first feeding structure layer and the second feeding structure layer are symmetrically distributed.

3. The array horn antenna transceiver system based on 77GHz millimeter wave radar according to claim 2, characterized in that: The curved waveguide structure of the bottom layer is matched with the microstrip-to-waveguide structure through the rectangular gap.

4. The array horn antenna transceiver system based on 77GHz millimeter wave radar according to claim 1, characterized in that: The lateral spacing between the receiving antennas Rx1, Rx2, and Rx3 is 0, the longitudinal spacing between the receiving antenna Rx1 and the receiving antenna Rx2 is 1.5 wavelengths, and the longitudinal spacing between the receiving antenna Rx2 and the receiving antenna Rx3 is 2 wavelengths; the lateral spacing between the receiving antenna Rx3 and the transmitting antenna Tx1 is 9 mm, and the longitudinal spacing is 2 wavelengths.

5. The array horn antenna transceiver system based on 77GHz millimeter wave radar according to claim 1, characterized in that: The horn array structure is a linear horn radiation structure, which shares a horn mouth, and the waveguide transmission parts of the horn antenna are independent of each other.

6. The array horn antenna transceiver system based on 77GHz millimeter wave radar according to claim 5, characterized in that: There is conductive glue between the three-layer structure, and the curved waveguide structure is made of aluminum; the materials of the array gap structure and the linear horn radiation structure are both made of aluminum or copper and filled with air.

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