A radar antenna system
By setting up uneven receiving microstrip antennas and processing modules in the radar antenna system, the phase difference of the echo signal is analyzed, and the pitch angle measurement function of the radar is realized, which solves the problem that the existing radar system cannot measure the pitch angle, and improves the Target recognition capability.
Patent Information
- Application Number
- CN201910110278.7
- Authority / Receiving Office
- CN · China
- Patent Type
- Patents(China)
- Current Assignee / Owner
- Filing Date
- 2019-02-11
- Publication Date
- 2024-12-13
- Estimated Expiration
- 2039-02-11
AI Technical Summary
Existing radar systems are difficult to measure the pitch angle of an object, and can only measure the angle of an object in the azimuth direction, and lack the pitch angle measurement function.
A radar antenna system is designed. By setting n-row receiving microstrip antennas in the radome, the first end of each row of receiving microstrip antenna is electrically connected to the processing module, and the second end of any adjacent two rows of receiving microstrip antennas is The unevenness makes the echo signal received by the adjacent receiving microstrip antenna have a phase difference, and the processing module obtains the target pitch angle by analyzing the phase difference.
The radar system's pitch angle measurement function of the target object is realized, which solves the problem that radar cannot measure pitch angle in the existing technology, and enhances the radar's target recognition ability.
Smart Images
Figure CN109669174B_ABST
Abstract
Description
Technical Field
[0001] The embodiments of the present invention relate to the field of automobile safety control technology, and in particular to a radar antenna system. Background Art
[0002] In current assisted driving applications, millimeter-wave radar sensors have become one of the mainstream detection sensors due to their moderate cost, strong environmental adaptability, and good long-distance detection capabilities. The operating frequency bands of automotive millimeter-wave radar products currently mainly include 24GHz and 77GHz. 77GHz is mainly used for long-distance detection. For example, Continental's ARS 408-21 and Delphi's ESR both have close-range wide field of view and long-distance detection capabilities. However, they can only measure the angle of an object in the azimuth direction, that is, the so-called three-dimensional radar (only has the ability to measure distance, speed, and azimuth angles), and it is difficult to identify the measured target. Summary of the invention
[0003] The invention provides a radar antenna system so as to enable the radar to have a pitch angle measurement function.
[0004] An embodiment of the present invention provides a radar antenna system, including:
[0005] Radome;
[0006] A processing module and at least one microstrip antenna group are located in the antenna cover, the microstrip antenna group includes a transmitting feed and a receiving feed respectively electrically connected to the processing module, the receiving feed includes n columns of receiving microstrip antennas, the receiving microstrip antennas have a first end and a second end, the first end of each column of the receiving microstrip antennas is electrically connected to the processing module, and the second ends of any two adjacent columns of the receiving microstrip antennas are not flush, the transmitting feed is used to send a transmitting antenna signal so that the target object feeds back an echo signal according to the transmitting antenna signal, the receiving microstrip antenna is used to receive the echo signal fed back by the target object, and the processing module is used to process the echo signals of the n columns of receiving microstrip antennas to obtain the pitch angle of the target object, and n is greater than or equal to 4.
[0007] Optionally, the transmitting feed source includes at least one column of transmitting microstrip antennas, and each column of the transmitting microstrip antennas is electrically connected to the processing module.
[0008] Optionally, in the microstrip antenna group, the transmitting feed source and the receiving feed source are arranged along the column direction of the receiving microstrip antenna.
[0009] Optionally, the radar antenna system includes a plurality of microstrip antenna groups, and the plurality of microstrip antenna groups are arranged along a first direction, wherein the first direction is parallel to the plane where the antenna cover is located and perpendicular to the column direction of the receiving microstrip antenna.
[0010] Optionally, the radome includes a cylindrical lens and a planar radome connected to the cylindrical lens;
[0011] At least one microstrip antenna group is correspondingly arranged on one side of the lower section of the cylindrical lens, and at least one microstrip antenna group is correspondingly arranged in the planar antenna cover. The column direction of the microstrip antennas in the microstrip antenna group is parallel to the axial direction of the cylindrical lens.
[0012] Optionally, the lower section of the cylindrical lens is pressed and connected to the planar antenna cover by adhesive.
[0013] Optionally, the cylindrical lens and the planar antenna cover are integrally formed.
[0014] Optionally, the directrix of the cylindrical lens is a parabola or a semicircle.
[0015] Optionally, the dielectric constant of the material of the radome is 2.5-3.
[0016] Optionally, the processing module includes at least one transmitting chip and at least one receiving chip, the transmitting chip is electrically connected to at least one of the transmitting feed sources, and the receiving chip is arranged in a one-to-one correspondence with the receiving feed sources and is electrically connected.
[0017] Optionally, the receiving microstrip antenna is a series-fed microstrip antenna.
[0018] The present invention arranges n columns of receiving microstrip antennas in a radome, the first end of each column of receiving microstrip antennas is electrically connected to a processing module, and the second ends of any two adjacent columns of receiving microstrip antennas are not flush, so that echo signals of the same target received by the adjacent receiving microstrip antennas have a phase difference; the processing module processes the echo signals received by the n columns of receiving microstrip antennas, and can obtain the pitch angle of the target by analyzing the phase difference, thereby solving the problem that the radar in the prior art cannot measure the pitch angle, and realizing the pitch angle measurement function of the radar to the target object. BRIEF DESCRIPTION OF THE DRAWINGS
[0019] Figure 1 A schematic diagram of the structure of a radar antenna system provided by an embodiment of the present invention;
[0020] Figure 2 A schematic diagram of the structure of a radar antenna system provided by an embodiment of the present invention;
[0021] Figure 3 A schematic diagram of a top view of a radome provided in an embodiment of the present invention;
[0022] Figure 4 A schematic diagram of the longitudinal section structure of a radome provided in an embodiment of the present invention;
[0023] Figure 5 A schematic diagram of a simulation of the beam direction of a receiving microstrip antenna in the azimuth plane provided by an embodiment of the present invention. DETAILED DESCRIPTION
[0024] The present invention will be further described in detail below in conjunction with the accompanying drawings and embodiments. It is to be understood that the specific embodiments described herein are only used to explain the present invention, rather than to limit the present invention. It should also be noted that, for ease of description, only parts related to the present invention, rather than all structures, are shown in the accompanying drawings.
[0025] Figure 1 A schematic diagram of the structure of a radar antenna system provided by an embodiment of the present invention, referring to Figure 1 As shown, the radar antenna system provided by the embodiment of the present invention includes: a radome 11, a processing module 12 located in the radome 11 and at least one microstrip antenna group 13, the microstrip antenna group 13 includes a transmitting feed 131 and a receiving feed 132 respectively electrically connected to the processing module 12, the receiving feed 132 includes n columns of receiving microstrip antennas 1321, the receiving microstrip antennas 1321 have a first end 13211 and a second end 13212, the first end 13211 of each column of receiving microstrip antennas 1321 is electrically connected to the processing module 12, and the second ends 13212 of any two adjacent columns of receiving microstrip antennas 1321 are not flush, the transmitting feed 131 is used to send a transmitting antenna signal so that the target object feeds back an echo signal according to the transmitting antenna signal, the receiving microstrip antenna 1321 is used to receive the echo signal fed back by the target object, and the processing module 12 is used to process the echo signals of the n columns of receiving microstrip antennas 1321 to obtain the pitch angle of the target object, where n is greater than or equal to 4.
[0026] Specifically, when the radar antenna system is working, the transmitting feed source 131 sends a transmitting antenna signal into the air, and the transmitting antenna signal will feed back an echo signal after being reflected by the target object, and the receiving microstrip antenna 1321 will receive the echo signal fed back by the target object. When setting up the radar antenna system, n columns of receiving microstrip antennas 1321 are perpendicular to the ground, and adjacent receiving microstrip antennas 1321 are staggered in the elevation direction, so that the reflected echo signals of the same target received by adjacent receiving microstrip antennas 1321 have a phase difference. The processing module processes the echo signals received by the n columns of receiving microstrip antennas 1321, and obtains the elevation angle of the target object by analyzing the phase difference between the echo signals received by each column of receiving microstrip antennas 1321.
[0027] The technical solution of the embodiment of the present invention is to arrange n columns of receiving microstrip antennas in the antenna cover, the first end of each column of receiving microstrip antennas is electrically connected to the processing module, and the second ends of any two adjacent columns of receiving microstrip antennas are not flush, so that the echo signals of the same target received by the adjacent receiving microstrip antennas have a phase difference; the processing module processes the echo signals received by the n columns of receiving microstrip antennas, and can obtain the pitch angle of the target by analyzing the phase difference, thereby solving the problem that the radar in the prior art cannot measure the pitch angle, and realizing that the radar has the angle measurement function in the pitch direction.
[0028] Optionally, the transmitting feed 131 includes at least one column of transmitting microstrip antennas 1311, and each column of transmitting microstrip antennas 1311 is electrically connected to the processing module 12. The number of transmitting microstrip antennas 1311 can be set according to the actual demand of the radar for azimuth detection. The more the number of transmitting microstrip antennas 1311 is, the larger the azimuth range that the radar can detect is. If the number of transmitting microstrip antennas 1311 is too large, the manufacturing cost of the radar antenna system will be increased. Exemplarily, the transmitting feed 131 includes two columns of transmitting microstrip antennas 1311.
[0029] Figure 2 A schematic diagram of the structure of a radar antenna system provided by an embodiment of the present invention, referring to Figure 2 As shown, optionally, in the microstrip antenna group 13, the transmitting feed 131 and the receiving feed 132 are arranged along the column direction 141 of the receiving microstrip antenna 1321, and the echo signal of the RF signal transmitted by the transmitting feed 131 and reflected by the target object is received by the receiving feed 132 in the same column.
[0030] Optionally, the radar antenna system includes multiple microstrip antenna groups 13, and the multiple microstrip antenna groups 13 are arranged along a first direction 142. The first direction 142 is parallel to the plane where the antenna cover 11 is located and perpendicular to the column direction 141 of the receiving microstrip antenna 1321. The multiple microstrip antenna groups 13 can expand the wide-angle detection function of the radar.
[0031] Figure 3 A schematic diagram of a top view of a radome provided in an embodiment of the present invention, Figure 4 A schematic diagram of the longitudinal section structure of the antenna cover provided in an embodiment of the present invention, referring to Figure 3 and Figure 4As shown, optionally, the radome 11 includes a cylindrical lens 111 and a planar radome 112 connected to the cylindrical lens 111, at least one microstrip antenna group 13 is correspondingly arranged on one side of the plane of the cylindrical lens 111, and at least one microstrip antenna group 13 is correspondingly arranged in the planar radome 112, and the column direction of the microstrip antennas in the microstrip antenna group 13 is parallel to the axial direction of the cylindrical lens 111. Exemplarily, a microstrip antenna group 13 is correspondingly arranged on one side of the plane of the cylindrical lens 111, and a microstrip antenna group 13 is correspondingly arranged in the planar radome 112. Since the cylindrical lens 111 has a focusing function, the cylindrical lens 111 is combined with the microstrip antenna array to realize the amplitude angle measurement function of the orientation plane and the phase angle measurement function of the pitch plane in the far field of view, so that the microstrip antenna group 13 corresponding to the cylindrical lens 111 can detect target objects far away from the radar, and realize the far field detection function of the radar.
[0032] The embodiment of the present invention adopts a focal plane array staring imaging system based on cylindrical lens focusing. Compared with other systems such as mechanical scanning and multi-beam electronic scanning, it does not require a servo device and is relatively simple in structure. It can further achieve real-time tracking of dynamic targets through ranging, speed measurement, azimuth angle measurement capabilities and pitch angle measurement capabilities without introducing any scanning mechanism.
[0033] Optionally, the lower section of the cylindrical lens 111 is pressed and connected to the planar radome 112 by an adhesive so that the cylindrical lens 111 is located on one side of the radome 11, making the radome 11 easy to process; alternatively, the cylindrical lens 111 and the planar radome 112 are integrally formed to simplify the manufacturing process, making the radar antenna system miniaturized and compact, and also facilitating mass production of the radome.
[0034] Optionally, the directrix of the cylindrical lens 111 is a parabola or a semicircle. When the radar antenna system is working, the plane where the directrix of the cylindrical lens 111 is located is parallel to the horizontal plane. The directrix of the cylindrical lens 111 is a parabola, which can make the design of the antenna cover 11 more flexible. The directrix is a semicircle, which facilitates the processing of the antenna cover 11.
[0035] Optionally, the cylindrical lens 111 and the planar radome 112 are made of the same material with a dielectric constant of 2.5-3. If the dielectric constant is too small, the thickness of the cylindrical lens 111 will increase, thereby increasing the attenuation of the RF signal or echo signal propagating in the cylindrical lens 111; if the dielectric constant is too large, the reflectivity of the radome 11 will also increase, increasing the loss of the RF signal or echo signal passing through the radome 11. Exemplarily, the dielectric constant of the radome 11 material is 2.6.
[0036] Continue to refer Figure 2As shown, optionally, the processing module 12 includes at least one transmitting chip 121 and at least one receiving chip 122 , the transmitting chip 121 is electrically connected to the transmitting feed source 131 , and the receiving chip 122 is arranged in a one-to-one correspondence with the receiving feed source 132 and is electrically connected.
[0037] Exemplarily, the radar antenna system includes two microstrip antenna groups 13, namely, a first microstrip antenna group and a second microstrip antenna group. The first microstrip antenna group includes a first transmitting feed and a first receiving feed, and the second microstrip antenna group includes a second transmitting feed and a second receiving feed. The first microstrip antenna group is arranged on one side of the plane of the cylindrical lens 111, and the second microstrip antenna group 13 is arranged on one side of the plane antenna cover 112. The processing module 12 includes a transmitting chip 121 and two receiving chips 122. The transmitting chip 121 is electrically connected to the first transmitting feed and the second transmitting feed. The two receiving chips 122 are respectively arranged and electrically connected to the first receiving feed and the second receiving feed in a one-to-one correspondence. The receiving chip 122 has multiple receiving channels, and the receiving microstrip antenna 1321 is respectively connected to each receiving channel of the receiving chip 122 through a feeder. Among them, the transmitting chip 121 is used to modulate the signal and transmit the modulated RF signal to the first transmitting feed and the second transmitting feed for transmission. Optionally, the transmitting chip 121 transmits the RF signal to the first transmitting feed and the second transmitting feed in time division, so that the first transmitting feed and the second transmitting feed transmit the RF signal alternately, and the RF signal transmitted by the first transmitting feed is received by the first receiving feed; the RF signal transmitted by the second transmitting feed is received by the second receiving feed, so that the first microstrip antenna group and the second microstrip antenna group simultaneously detect the target object in the far field of view or near field of view of the radar. The receiving chip 122 is used to demodulate the echo signal received by the receiving feed 132 into a baseband signal, so as to facilitate the subsequent processing of the signal. Optionally, the transmitting chip 121 adopts the RTN7735 chip, the receiving chip 122 adopts the RRN7746 chip, one RTN7735 chip is cascaded with two RRN7746 chips, the RTN7735 chip is electrically connected to the first transmitting feed source and the second transmitting feed source, and the RRN7746 chip includes 4 receiving channels and can be connected to 4 receiving microstrip antennas 1321, thereby realizing a compact two-transmit and eight-receive radar antenna system.
[0038] Optionally, the receiving microstrip antenna 1321 is a series-fed microstrip antenna to make the structure of the radar antenna system more compact.
[0039] Figure 5 A schematic diagram of a simulation of the beam direction of the receiving microstrip antenna in the azimuth plane provided by an embodiment of the present invention, referring to Figure 2 and Figure 5As shown, the microstrip antenna group 13 corresponding to the plane side of the cylindrical lens 111 includes a receiving feed source 132, and the receiving feed source 132 includes 4 columns of receiving microstrip antennas 1321, which are RX1, RX2, RX3 and RX4 respectively. The 4 columns of receiving microstrip antennas 1321 combined with the cylindrical lens 111 will form four directional narrow beams in the horizontal plane. The beam width formed by each column of receiving microstrip antennas 1321 in the azimuth plane through the cylindrical lens is 6° respectively. The 4 columns of receiving microstrip antennas 1321 covers a total of ±12° in the azimuth plane through the cylindrical lens 111, and the gain of the receiving microstrip antenna 1321 is 25dBi. Optionally, by designing the shape of the cylindrical lens 111, the beam width formed by the receiving microstrip antenna 1321 in the azimuth plane can be 5°-7°. If the receiving feed source 132 includes 4 columns of receiving microstrip antennas 1321, the 4 columns of receiving microstrip antennas 1321 can cover ±10° to ±14° in the azimuth plane through the cylindrical lens 111.
[0040] Continue to refer Figure 1 As shown, optionally, the radar antenna system provided in the embodiment of the present invention further includes a microwave circuit board 14 for carrying the microstrip antenna group 13 and the processing module 12. Optionally, the microwave circuit board 14 is made of Rogers 3003 board material.
[0041] The existing radar systems (phased array system, MIMO system) are relatively complex or have incomplete functions. The radar antenna system provided by the embodiment of the present invention adopts a combination of a microstrip feed array and a cylindrical lens. In the far field, the radar antenna system realizes the amplitude-comparison angle measurement function in the azimuth plane and the phase-comparison angle measurement function in the elevation plane by combining the cylindrical lens with the microstrip array; in the near field, two groups of microstrip antennas with two transmitters and eight receivers are formed by cascading the transmitting chip and the receiving chip, realizing the phase-comparison angle measurement function of the radar antenna system in the azimuth plane and the elevation plane, and expanding the short-range wide-angle detection function of the radar antenna system. Thus, the performance of the radar is improved without increasing the cost, size and system complexity of the radar antenna system, and the angle measurement functions of the radar antenna system in the short-range wide-field elevation plane and azimuth plane and the angle measurement functions of the long-range narrow-field elevation plane and azimuth plane are realized, so that the radar antenna system has a certain target recognition capability.
[0042] The radar antenna system provided in the embodiment of the present invention can operate in millimeter wave frequency bands, such as 24 GHz and 77 GHz. Millimeter waves have the advantage of strong ability to penetrate fog, smoke, and dust. The radar antenna system provided in the embodiment of the present invention can also operate in other frequency bands, which is not limited here.
[0043] Note that the above are only preferred embodiments of the present invention and the technical principles used. Those skilled in the art will understand that the present invention is not limited to the specific embodiments described herein, and that various obvious changes, readjustments and substitutions can be made by those skilled in the art without departing from the scope of protection of the present invention. Therefore, although the present invention has been described in more detail through the above embodiments, the present invention is not limited to the above embodiments, and may include more other equivalent embodiments without departing from the concept of the present invention, and the scope of the present invention is determined by the scope of the appended claims.
Claims
1. A radar antenna system, characterized in that: include: Radome; A processing module and at least one microstrip antenna group located in the antenna cover, the microstrip antenna group includes a transmitting feed and a receiving feed respectively electrically connected to the processing module, the receiving feed includes n columns of receiving microstrip antennas, the receiving microstrip antennas have a first end and a second end, the first end of each column of the receiving microstrip antennas is electrically connected to the processing module, and the second ends of any two adjacent columns of the receiving microstrip antennas are not flush, the transmitting feed is used to send a transmitting antenna signal so that the target object feeds back an echo signal according to the transmitting antenna signal, the receiving microstrip antenna is used to receive the echo signal fed back by the target object, and the processing module is used to process the echo signals of the n columns of receiving microstrip antennas to obtain the pitch angle of the target object, where n is greater than or equal to 4; The processing module includes at least one transmitting chip and at least one receiving chip, wherein the transmitting chip is electrically connected to at least one transmitting feed source, and the receiving chip is arranged in a one-to-one correspondence with the receiving feed source and is electrically connected; The at least one transmitting chip is cascaded with the at least one receiving chip; The radome includes a cylindrical lens and a planar radome connected to the cylindrical lens; At least one microstrip antenna group is correspondingly arranged on one side of the lower cross section of the cylindrical lens, and at least one microstrip antenna group is correspondingly arranged in the planar antenna cover, and the column direction of the microstrip antennas in the microstrip antenna group is parallel to the axial direction of the cylindrical lens; The directrix of the cylindrical lens is a parabola or a semicircle.
2. The radar antenna system according to claim 1, characterized in that: The transmitting feed source includes at least one column of transmitting microstrip antennas, and each column of the transmitting microstrip antennas is electrically connected to the processing module.
3. The radar antenna system according to claim 1, characterized in that: In the microstrip antenna group, the transmitting feed source and the receiving feed source are arranged along the column direction of the receiving microstrip antenna.
4. The radar antenna system according to claim 1, characterized in that: The radar antenna system includes a plurality of microstrip antenna groups, and the plurality of microstrip antenna groups are arranged along a first direction, wherein the first direction is parallel to the plane where the radome is located and is perpendicular to the column direction of the receiving microstrip antennas.
5. The radar antenna system according to claim 1, characterized in that: The lower section of the cylindrical lens is pressed and connected to the planar antenna cover by adhesive.
6. The radar antenna system according to claim 1, characterized in that: The cylindrical lens and the planar antenna cover are integrally formed.
7. The radar antenna system according to claim 1, characterized in that: The dielectric constant of the material of the radome is 2.5-3.
8. The radar antenna system according to claim 1, characterized in that: The receiving microstrip antenna is a series-fed microstrip antenna.