Recent Advances in Microwave Applications of Thin Ferroelectric Films at the NASA Glenn Research Center

Abstract

We report on recent developments in microwave applications and understanding of thin Ba 50 Sr 50 TiO 3 films. Most of our recent efforts have focused on developing low loss, wide band phase shifters from X-band (8.4 GHz) to Ka-Band (26.5 GHz) for scanning reflectarray antennas. Attempts to reduce tanδ by Mn-doping Ba 50 Sr 50 TiO 3 films are briefly discussed. We have demonstrated a hybrid device at X-band that produces in excess of 300 degrees of phase shift with about 3.5 dB insertion loss and greater that 10% bandwidth. Preliminary results are presented here. The effects of mild (600 rad Si) proton radiation on device performance will also be discussed. Preliminary results on optical phase shifters will be included.

Reconfigurable Microstrip Antennas

“…In order to minimize the losses of ferroelectric materials, for example, several researchers have developed ferroelectric materials in thin film form while still providing a degree of tunability [1][2][3]. The use of thin films, however, means that the achievable tuning range of these structures is not as large as if the material could be used as the sole substrate without losses.…”