AgTa0.5Nb0.5O3 thin film microwave coplanar waveguide tunable capacitors

400 nm thick AgTa0.5 Nb0.5O3 (ATN) films have been prepared by pulsed laser deposition technique on LaAlO3 (001) and sapphire (Al2O3-01 (1) under bar2, r-cut) single crystal substrates. Comprehensive X-ray diffraction analysis showed epitaxial quality of ATN/LaAlO3 films and preferentially (001) orientation of ATN/Al2O3 films. Voltage tunable microwave capacitors were fabricated by lift-off technique on the surface of ferroelectric films. Microwave on-wafer tests were performed in the range from 1 to 40 GHz. Frequency dispersion is about 4.3%, voltage tunability is 4.7% @ 20 GHz and 200 kV/cm, loss tangent similar to 0.068 @ 20 GHz, K-factor = tunability/tan delta is ranged from 124% @ 10 GHz to 35% @ 40 GHz.