FMCW technology is an emerging radar measurement technology, commonly known as Frequency ModulatedContinuous WaveRadar (FMCW Radar).
Compared to traditional pulse radar technology, FMCW technology uses continuous wave signals, which have significant and superior characteristics such as higher resolution, smaller power consumption, and longer ranging range. FMCW technology utilizes signal modulation to achieve distance measurement. In this mode, the radar transmitter emits continuous frequency modulated waves to the target object, and the receiver samples the signal and obtains the distance and velocity information between the target object and the radar transmitter through frequency analysis. Compared to traditional pulse radar technology, FMCW technology has higher signal-to-noise ratio and better resistance to multipath interference.
FMCW technology 80 GHz Radar of Algorithm Description
The ranging principle of FMCW technology uses the detection of echo delay to calculate the current distance, and then calculates the current measurement speed by detecting the Doppler frequency shift component of the echo. The schematic diagram of its transmission signal and echo signal is shown in Figure 1.
The echo signal can be regarded as the delay signal of the transmitted signal for calculation, and the echo delay and frequency are defined as linear relationships, so that the current distance can be calculated by calculating the echo delay. The FMCW ranging formula can be obtained as follows:
d=c×Ts×f/2×Bw
When detecting the operating situation, the echo signal has a Doppler effect, and there is a certain frequency shift between the echo signal and the transmitted signal. By calculating the frequency shift of the echo, the current speed can be calculated. The FMCW technology adopts the FFT frequency shift processing method, and its speed measurement formula is derived as follows:
FFT formula:
Velocity obtained from Doppler phase change:
Among them, Tc is the interval between adjacent echo periods.
To obtain: v= Δ V · n
