A Light-Weight Tunable Liquid Crystal Phase Shifter for an Efficient Phased Array Antenna

In this paper, we present the design and recent measurements of a satellite Ka-band phase shifter based on Liquid Crystal (LC) technology in hollow waveguide topology. The phase shifter is intended to be fully integrated into each branch of a hollow waveguide feeding network for a compact, lightweight Tx/Rx phased array antenna. Mounted on a geostationary satellite, this antenna can be used to establish the link between a low earth orbit satellite and a ground station. A key feature of the presented design is its high efficiency in terms of phase shift versus insertion loss which is particularly important for Tx operation. Moreover, the design can be optimised for low weight and high integration into the mechanical concept of the antenna. Measurements have been carried out from 21 GHz to 35 GHz and are presented for magnetic biasing as well as electric biasing. Performance is discussed in terms of insertion loss, matching and total phase shift.