Voltage Driven Phase Shifters for Phase Reference Distribution System in SINBAD

This document presents a realization of an analog voltage driven 3 GHz phase shifter circuits for the phase reference distribution system (PRDS) that is currently under development by the Institute of Electronic Systems (ISE) for SINBAD (Short Innovative Bunches and Accelerators at DESY), in Hamburg. Presented phase shifter structure is based on a topology of a reflection phase shifter, made with a 3 dB hybrid coupler structure and varactor diodes acting as adjustable reflections. The realization is planned to be used as a substitute for obsolete phase shifter ICs and for this reason the area taken by the phase shifter in the PCB should be small. That is why we decided to use commercially available LTCC hybrid couplers, which allow widening the frequency band that can be covered by the phase shifter, area reduction and maintaining good return loss and insertion loss of the device, which is of utmost importance in SINBAD PRDS.