Parallel-plate waveguide bulk ceramic ferroelectric phase shifters

A phase shifter is reported, which is based on bulk Ba/sub 0.63/Sr/sub 0.37/TiO/sub 3/(1.5MgO) ceramic parallel-plate waveguide. The sizes of the phase shifter are 35 /spl times/ 12mm. The device is experimentally characterized under 0-900V DC voltage using external bias tees and is intended for operation at high powers. The obtained figure of merit is 50deg/dB at /spl sim/3.5GHz. It is shown that with higher voltages this figure of merit may be improved up to /spl sim/100deg/dB.