Abstract: A method and apparatus for a phase shifter includes a controller controlling a voltage controlled phase shifting circuit for shifting the phase of a high frequency input signal. The phase shifting circuit includes microstrip elements arranged in a 3 dB hybrid structure, and also includes first and second reverse-biased diodes electrically connected to the microstrip elements and operating as varactors. The controller drives a D/A converter to control the bias voltage of the phase shifting circuit and thereby to adjust the phase shift of a high frequency output signal relative to the high frequency input signal.