Automotive Radar System Basics: A Tutorial
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This tutorial covers the basics of automotive radar systems, including specifications and frequency bands. While radar systems have diverse applications, sharing the same fundamental operational principles, automotive radar is specifically designed to enhance car safety.
Let’s delve into the fundamental operation of a radar system. Typically, a radar comprises two primary components: a transmitter and a receiver. The transmitter emits electromagnetic (EM) waves toward a target, and the receiver detects the echo reflected from that target.
This received echo signal represents only a fraction of the transmitted signal. It undergoes amplification, downconversion, and subsequent processing to extract key information such as the target’s range and size. Furthermore, the target’s direction can be determined based on the angle of arrival of the echoed wave. The relative velocity of the target is calculated using the Doppler shift of the returned signal.
Automotive Radar Configurations
There are two main configurations used in automotive radar applications:
- Monostatic Radar: Employs a single antenna for both transmission and reception. A duplexer provides isolation between the transmitter and receiver components.
- Bistatic Radar: Utilizes separate antennas for transmission and reception.
Automotive Radar System Specifications
The following table outlines typical specifications for automotive radar systems:
Table 1: Automotive Radar System Specifications
Specification | Value |
---|---|
System type | Pulse |
Band | 76 to 77 GHz |
Emission Bandwidth (BW) | up to 500 MHz |
Max. EIRP | up to 20 Watts |
Average EIRP | < 10 mWatt |
Antenna Beamwidth (MAX.) | 4 degree elevation, 15 degree azimuth |
Frequency Bands for Automotive Radar
The following table shows the frequency bands used by various organizations for automotive radar applications.
Table 2: Automotive Radar Frequency Bands
Organization | Frequency Bands |
---|---|
CEPT (Europe) | 76 to 77 GHz |
ETSI (Europe) | 76 to 77 GHz |
FCC (USA) | 46.7 to 46.9 GHz, 76 to 77 GHz |
ITU | 60 to 61 GHz, 76 to 77 GHz |
MPT (JAPAN) | 60 to 61 GHz, 76 to 77 GHz |