Ka-band RF MEMS phase shifters for energy starved millimetre-wave radar sensors

Low-loss millimetre-wave RF MEMS phase shifters made on quartz are assessed with respect to a Ka-band low-power multifunctional radar sensor application. A loaded line type of phase shifter circuit presents a phase shift of 22.3° and a loss of 0.4 dB at 35 GHz. A switched line phase shifter gives 187° of phase shift and 1.5 dB of loss at 30 GHz (i.e. a FoM=122°/dB). We estimate that a 5-bit loaded line/switched line MEMS phase shifter circuit can achieve a loss of 4 dB at 35 GHz which could reduce by a factor 2 the required transmit DC power level in a Ka-Band energy starved phased array radar system.