Measurement of Residual Phase Noise Of Amplifiers at 80 Ghz Using Interferometric Measurement Technique

The additive and residual phase noise from power amplifiers or multipliers contributes unwanted noise in the signal path. For automotive RADAR sensors operating at 80 GHz, designers require phase noise in the transmission path to be lower than -130 dBc/Hz at a 100 kHz offset, with even lower levels desired to enhance the signal-to-noise ratio (S/N) for detecting small moving targets. This paper presents an interferometric measurement technique combined with a phase noise test system that allows for the characterization of additive and residual phase noise in amplifiers down to -150 dBc/Hz at a 100 kHz offset, even in the microwave range at 80 GHz.