Frequency modulated continuous wave (FMCW) radar is a type of radar system that operates by continuously transmitting a signal with a frequency that varies linearly with time. This frequency modulation creates a continuous waveform that is typically swept over a certain frequency range. In FMCW radar, the transmitted signal is mixed with the received signal to generate an intermediate frequency (IF) signal, from which range information can be derived based on the frequency difference between the transmitted and received signals.
This principle allows the FMCW radar to measure the target range with high accuracy, as well as a target speed by measuring the Doppler shift in the reflected signal.
The principle of FMCW radar revolves around the transmission of a continuous wave signal that changes frequency linearly over time. This frequency modulation creates a signal that rises and falls in frequency over a specified range. When this modulated signal encounters a target, such as an object or terrain, part of the signal is reflected back to the radar receiver.
By comparing the frequency of the transmitted signal with that of the received signal, the FMCW radar can determine the range to the target based on the difference in frequencies. The rate of change of frequency transmitted determines the range resolution of the radar system, with faster ramp rates providing finer resolution.
Continuous wave (CW) radar is a type of radar system that continuously emits a continuous wave signal without modulation.
Unlike pulsed radar systems that emit short bursts of high-power radio frequency energy, CW radar works by transmitting a regular waveform at a specific frequency. CW radar is commonly used in applications where accurate target speed measurement is required, such as speed guns used by law enforcement to monitor vehicle speeds. It is also used in Doppler radar systems for weather applications to measure wind speed and direction.
The simplicity and ability of CW radar to measure continuous frequency changes make it suitable for specific applications requiring continuous monitoring and measurement of Doppler shifts
