Ferroelectric Phase Shifters for VHF and UHF

The analysis, construction, and performance of compact surface wave ferroelectric phase shifters suitable for operation in the100-to1000-MC frequency range are described. Although this ferroelectric loaded parallel-plane structure is a very low impedance structure, a satisfactory terminal impedance matching technique has been devised. Kilovolt level voltages are needed; but since the current required to maintain or rapidly shift phase is low, the over-all control power requirements are at least an order of magnitude less than those for comparable ferrite phase shifters. One of these room temperature operable phase shifters provided 348° of phase shift at 207 Mc. It had an insertion loss which varied from 3.7 to 2.2 db over a zero- to 4000-volt range of applied dc control voltage.