A low-phase-noise 122-GHz FMCW radar sensor for distributed networks

In this work, a 122-GHz radar sensor for cooperative bistatic networks using a transceiver chip with integrated antennas is presented. The presented sensor shows a phase-noise spectral power density of -83 dBc/Hz at 10 kHz offset and absolute phase deviations of less than 0.65 radians rms for a ramp with 1 GHz bandwidth and 1 ms sweep-time. These parameters make it suitable to be used in cooperative setups or sensor networks with two or more sensor nodes. The low phase noise is achieved by stabilizing the transceiver voltage-controlled oscillator (VCO) in a phase-locked loop (PLL) with a reference signal, which is modulated by a direct digital synthesizer (DDS). A radar network of two sensor nodes was built to perform monostatic and bistatic measurements.