New calibration method used for active phased array antennas

This paper deals with the design of a Ku-band phased array antenna where phase shifting is performed through the use of reflection-type phase shifters controlled with varactor diodes. The paper describes a new calibration method which can provide the bias voltage to be applied to each phase shifter in order to scan the beam in the desired direction. This method is based on the use of a microstrip line, coupled with the feeding line of each radiating element, which provides the real phase feeding the radiating element. Measured scanned radiation patterns of a Ku-band phased array integrating these calibration lines are presented.