A GaAs MMIC-based dual channel microwave phase detector at X-band

A microwave phase detector at X-band with dual channels fabricated using Au surface micromachining technology is presented. The detector is composed of power dividers, power combiners, phase shifters and thermoelectric power sensors. Besides the initial phase difference, the detector introduces additional 45° phase lead and 45° phase lag in two channels. Microwave power sensors are employed to detect the output powers, and the initial phase difference can be finally calculated from anti-trigonometric function of the normalized output in -180° to +180°. The fabrication is compatible with GaAs MMIC process. The measured S-parameters show that the detector has reflection loss less than -12dB over a bandwidth of more than 66% centered at 10GHz and isolation less than -13dB, and the normalizations of measured output voltages agree well with the calculated results in three situations.