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CN-116347759-B - Circuit board assembly, radar and vehicle

CN116347759BCN 116347759 BCN116347759 BCN 116347759BCN-116347759-B

Abstract

The embodiment of the application provides a circuit board assembly, a radar and a vehicle. The circuit board assembly includes a circuit board, at least one antenna, at least two radio frequency chips, and a first cover layer. The circuit board comprises a plurality of layers of core boards and a circuit layer arranged between two adjacent layers of core boards, wherein the circuit layer comprises a plurality of first transmission lines and a plurality of second transmission lines. The two ends of the second transmission line are respectively and electrically connected with the antenna and the second radio frequency chip, and the first cover layer is arranged on the circuit board, wherein the relative dielectric constant of the first cover layer is linearly related to the transmission speed of the first radio frequency signal, so that the speed ratio of the transmission speed of the first radio frequency signal to the transmission speed of the second radio frequency signal is equal to the length ratio of the first transmission line to the second transmission line. When the first transmission line and the second transmission line are wired, the limitation that the wiring length is the same is not needed to be considered, and when the requirements of wiring space and position are met, the first transmission line and the second transmission line can be arranged in a regular straight line shape as far as possible.

Inventors

  • ZENG YUANSONG
  • QIAN TONG
  • SHEN LIN
  • SHEN LINJIE

Assignees

  • 杭州海康威视数字技术股份有限公司

Dates

Publication Date
20260512
Application Date
20211224

Claims (11)

  1. 1. A circuit board assembly, comprising: the circuit board comprises a plurality of layers of core boards and a circuit layer arranged between two adjacent layers of core boards, wherein the circuit layer comprises a plurality of first transmission lines and a plurality of second transmission lines, wherein the lengths of any two first transmission lines are the same, and the lengths of any two second transmission lines are the same; At least one antenna; The antenna comprises a circuit board, at least two radio frequency chips, a first transmission line, a second transmission line, a first antenna, a second antenna, a first radio frequency chip, a second radio frequency chip, a first transmission line, a second transmission line and a second transmission line, wherein the at least two radio frequency chips are arranged on the circuit board and are respectively a first radio frequency chip and a second radio frequency chip; The first cover layer is arranged on the circuit board and covers the plurality of first transmission lines, wherein the relative dielectric constant of the first cover layer meets a first condition, and the first condition is that the relative dielectric constant of the first cover layer is linearly related to the transmission speed of the first radio frequency signal, and the speed ratio of the transmission speed of the first radio frequency signal to the transmission speed of the second radio frequency signal is equal to the length ratio of the first transmission line to the second transmission line.
  2. 2. The circuit board assembly of claim 1, wherein the circuit board assembly further comprises: The second cover layer is arranged on the circuit board and covers the plurality of second transmission lines, wherein the relative dielectric constant of the second cover layer meets a second condition, the second condition is that the relative dielectric constant of the second cover layer is linearly related to the transmission speed of the second radio frequency signal, the speed ratio of the transmission speed of the first radio frequency signal to the transmission speed of the second radio frequency signal is equal to the length ratio of the first transmission line to the second transmission line, and the relative dielectric constants of the first cover layer and the second cover layer are different.
  3. 3. The circuit board assembly of claim 1, wherein the at least one antenna comprises a transmitting antenna; the first transmission lines comprise a plurality of first transmitting transmission lines, and two ends of each first transmitting transmission line are respectively and electrically connected with the transmitting antenna and the first radio frequency chip; The plurality of second transmission lines comprise a plurality of second transmitting transmission lines, and two ends of each second transmitting transmission line are respectively and electrically connected with the transmitting antenna and the second radio frequency chip; The length ratio of the first transmitting transmission line and the second transmitting transmission line is n1, and the speed ratio of the transmission speed of the first radio frequency signal and the transmission speed of the second radio frequency signal is n1, n1>0.
  4. 4. The circuit board assembly of claim 1, wherein the at least one antenna comprises a receiving antenna; the plurality of first transmission lines further comprise a plurality of first receiving transmission lines, and two ends of each first receiving transmission line are respectively and electrically connected with the receiving antenna and the first radio frequency chip; The plurality of second transmission lines further comprise a plurality of second receiving transmission lines, and two ends of each second receiving transmission line are respectively and electrically connected with the receiving antenna and the second radio frequency chip; The length ratio of the first receiving transmission line to the second receiving transmission line is n2, and the speed ratio of the transmission speed of the first radio frequency signal to the transmission speed of the second radio frequency signal is n2, n2>0.
  5. 5. The circuit board assembly of claim 2, wherein the first cover layer and the second cover layer are co-layered.
  6. 6. The circuit board assembly of claim 1, wherein the material of the core board is the same as the material of the first cover layer.
  7. 7. The circuit board assembly of claim 1, wherein the first transmission line and the second transmission line are microstrip transmission lines, coplanar waveguide transmission lines, or grounded coplanar waveguide transmission lines.
  8. 8. The circuit board assembly according to any one of claims 1-7, wherein the first transmission line and the second transmission line are located on the same layer of the circuit layer.
  9. 9. The circuit board assembly of any one of claims 1-7, wherein at least one of a material, a width, and a thickness of the first transmission line and the second transmission line are the same.
  10. 10. A radar, the radar comprising: A housing; the circuit board assembly of any one of claims 1-9 disposed within the housing.
  11. 11. A vehicle comprising a vehicle body, and the radar of claim 10 disposed on the vehicle body.

Description

Circuit board assembly, radar and vehicle Technical Field The application relates to the technical field of radars, in particular to a circuit board assembly, a radar and a vehicle. Background In recent years, radar applications are becoming more and more widespread, such as millimeter wave radar, which is increasingly playing an important role in the fields of automobile assisted driving, security, medical health, and the like. The normal operation of the radar needs to be interconnected between each radio frequency port of the radio frequency chip and each antenna through a low-loss and low-dispersion radio frequency transmission line. In order to meet the requirement that the transmission phases from each antenna to the transmission line are the same within a certain bandwidth, geometric equal length between the transmission lines corresponding to each antenna channel is also required. In order to achieve equal length, a structure of extending geometric paths such as an S-bend is required to be introduced into the transmission line, the equal length wiring process is extremely complicated, and the insertion loss and the inter-channel mutual coupling caused by equal length wiring also restrict the further improvement of the radar performance. Disclosure of Invention The embodiment of the application provides a circuit board assembly, a radar and a vehicle, which are used for reducing wiring difficulty, improving radar radio frequency performance and shortening development period. In order to achieve the above purpose, the application adopts the following technical scheme: In a first aspect of an embodiment of the present application, a circuit board assembly is provided, including a circuit board, at least one antenna, at least two radio frequency chips, and a first cover layer. The circuit board comprises a plurality of layers of core boards and a circuit layer arranged between two adjacent layers of core boards, wherein the circuit layer comprises a plurality of first transmission lines and a plurality of second transmission lines, the lengths of any two first transmission lines are the same, and the lengths of any two second transmission lines are the same. The radio frequency chip is arranged on the circuit board and is respectively a first radio frequency chip and a second radio frequency chip, two ends of a first transmission line are respectively and electrically connected with the antenna and the first radio frequency chip, the first transmission line is used for transmitting first radio frequency signals between the antenna and the first radio frequency chip, two ends of a second transmission line are respectively and electrically connected with the antenna and the second radio frequency chip, the second transmission line is used for transmitting second radio frequency signals between the antenna and the second radio frequency chip, a first covering layer is arranged on the circuit board and covers a plurality of first transmission lines, wherein the relative dielectric constant of the first covering layer meets a first condition, and the first condition is that the relative dielectric constant of the first covering layer is linearly related to the transmission speed of the first radio frequency signals, and the speed ratio of the transmission speed of the first radio frequency signals to the transmission speed of the second radio frequency signals is equal to the length ratio of the first transmission line to the second transmission line. . According to the circuit board assembly, the transmission speed of the first radio frequency signal is adjusted through the first cover layer, so that the speed ratio of the transmission speed of the first radio frequency signal to the transmission speed of the second radio frequency signal is equal to the length ratio of the first transmission line to the second transmission line, and the same transmission phase from the antenna to the transmission line is ensured. Therefore, when the first transmission line and the second transmission line are wired, the limitation of the same wiring length is not needed to be considered, and when the requirements of wiring space and position are met, the first transmission line and the second transmission line can be arranged in a regular straight line shape as far as possible. Therefore, the first transmission line and the second transmission line are simple in wiring, the development period and the development difficulty of the radar are reduced, and the line length of the first transmission line and the line length of the second transmission line are shortened, so that lower transmission loss is brought. Optionally, the circuit board assembly further comprises a second cover layer, wherein the second cover layer is arranged on the circuit board and covers the plurality of second transmission lines, the relative dielectric constant of the second cover layer meets a second condition, the second condition is that the relat