Many high-performance automotive auxiliary systems rely on radar to collect information around the vehicle. They are used to accurately calculate the distance and relative speed between the vehicle and the vehicle in front according to the principle of reflected wave. Bosch's fourth generation long range radar sensor (lrr4) is designed on the basis of R & D and production experience of the third generation radar. The lrr4, the same as the previous generation, uses the 77 GHz band and has no removable parts. All the components are fixed on all parts of the vehicle to improve the stability of the system. Lrr4 radar sensor integrates two electronic boards, including microcontrollers of NXP and STMicroelectronics, and power management IC of Bosch. The RF board is an asymmetric structure based on hybrid PTFE / FR4 substrate, and is equipped with a planar antenna. Infineon 77 GHz SiGe monolithic microwave integrated circuit (MMIC) is used as high frequency transmitter and receiver.
Lrr4 comes from Bosch and is a multi-mode radar with six fixed radar antennas. Four centrally arranged antennas can provide high-speed recording of the environment, create a focused beam with an aperture angle of ± 6 ° and minimize traffic interference in adjacent lanes. For the near-field situation, the two external antennas of lrr4 can expand the field of view angle to ± 20 ° and the range is 5m, which can detect the vehicle entering or leaving the lane quickly.
APTIV's short range radar sensor, which consists of two transmitters and four receiver channels, operates in the 76-77 GHz frequency band, which is the standard configuration for automotive radar applications. PCB uses a single-chip microwave integrated circuit (MMIC) and several cavity waveguides. The RF PCB substrate is made of glass reinforced hydrocarbon based ceramic laminates and is completely free of PTFE.