In this paper, the components required for FMCW (Frequency-Modulated Continuous Wave) RADAR (Radio Detection and Ranging) system operating at 3GHz i.e. modulator circuit and video amplifier circuit are designed and tested. For this purpose, the RF (Radio Frequency) components were selected from microstrip trainer kit MST-523 of Feedback Instruments. The working of each component is analyzed through VNA (Vector Network Analyzer) and spectrum analyzer. The patch antennas provided in the kit were used as transmitter and receiver operating at 3 GHz. The modulator circuit is built with variable frequency and amplitude to modulate the signal from VCO (Voltage Controlled Oscillator). The triangular wave is selected for this purpose to modulate the VCO. The received signal is measured on spectrum analyzer and received power is measured at every integral multiple of wavelength to check working state of antenna and change in power. The Low pass filter circuit is also designed to filter out the higher frequencies after the mixer stage. The RADAR range is calculated based on measurement of the system.