Cross-coupled planar microwave filters were fabricated using YB 2Cu3O7-δ superconducting thin films deposited on both sides of a LaAlO3 single crystal substrate by pulsed laser deposition. The hairpin resonator geometry allows one to miniaturize the 3-GHz filters by compacting the entire filter onto a substrate with dimensions 0.5 cm × 1 cm. By adjusting the relative spacing among the resonators to establish adequate couplings, filters with very sharp rejection skirt and extremely small insertion loss in passband were obtained.
- Compact miniaturized hairpin resonators
- High-temperature superconducting (HTS) thin films
- Planar microwave filters