The paper focuses on the latest progress of the power handling capabil
ity of HTS thin film materials and microwave circuits particularly fil
ters. The surface resistance vs. rf magnetic field data measured at 8.
14 GHz and different temperatures for YBa2Cu3O7-delta and Tl2Ba2CaCu2O
8 films are presented. A 3-pole 6.04 GHz 1.3% filter with polygon-shap
e resonators and back-side coupling circuits were designed, fabricated
and tested up to 74 watts transmitting power at 77 K, which is suitab
le for applications in the transmitters.