Accurate digital control and rotation of the phase of microwave signals

A method of remotely controlling the phase and phase rates of low-frequency reference signals using digital techniques is described. These signals can, in turn, be used to control the phase of a microwave local oscillator in a phase array. The system, which was designed to control the phase of the local oscillators in a radio astronomy array called the Australian Telescope, gives phase resolution of 0.18° and phase rates up to 2×10⁴ rad/s