Doppler Effect → Velocity
Reflected waves from a moving object experience a change in received frequency (Doppler Effect).
As the object comes closer, the frequency increases; as it moves away, the frequency decreases.
This frequency shift (Doppler shift) can be used to calculate the velocity.
|
|
|||
1. Doppler Effect in Continuous Wave (CW)
A continuous sinusoidal signal with a fixed frequency is transmitted toward a target.
When the target is moving, the reflected signal exhibits a frequency shift proportional to its radial velocity.
This frequency difference is used to determine the target’s speed.
The detection of this frequency difference is described in the Doppler FFT section of ANL.
2. Doppler Effect in FMCW
In FMCW radar, a time delay due to target range creates a frequency difference between the transmitted and received signals.
In addition, when the target moves with a certain velocity, an extra Doppler-induced frequency shift is added,
so the observed frequency difference contains both range and velocity components.
The extraction of the range-induced and Doppler-induced frequency components is described in the Range FFT and Doppler FFT sections of ANL.
Radar Sensor SoC & Module
WiFi IoT Module
5G/LTE/CAT-M1/NB-IoT
WiSUN/HaLow/Thread Module
