Wide band phase shifters

Latching ferrite phase shifters, in waveguide, with digital control have been used in the past and have, in particular, found application in phased arrays. The devices are capable of extremely wide bandwidth. The authors present the configuration of a phase shifter constructed with Trans Tech TT1-109 ferrite. It consists of four digital bits giving differential phase shifts of nominally 180, 90, 45 and 22.5 degrees. The wide band response is given and shows the performance of the 180-degree bit. Also shown is the insertion loss of a complete phase shifter with four bits. All measurements were carried out with the ferrite in a state of magnetic remanence obtained from a current pulse of 4 A. The useful range of the phase shifter is seen to extend from the upper edge of S band through X band.