A Simple-Structure FMCW Radar Test System Using PLL-Gunn Oscillator and Fundamental Mixer in 79 GHz Band

In this study, a simple frequency-modulated continuous wave (FMCW) radar test system for an anti-collision automobile radar in the 79 GHz band has been developed. This system consists of a down-converter based on a fundamental mixer with a phase-locked loop-Gunn oscillator and a mixed domain oscilloscope or a digital oscilloscope. This system can evaluate an FMCW signal in the time domain, which includes the evaluation of the chirp rate, chirp width, chirp length, and linearity. By employing the Gunn oscillator, the down-converter attains a very simple configuration. The down-converter has a conversion gain of 7.8 dB at 79 GHz in typical conditions and a bandwidth of 4 GHz. In this study, we explain the development of the radar test system and demonstrate the same using an FMCW chipset evaluation board.