Miniaturized hairpin superconducting filters for telecommunications applications

Using miniaturized hairpin resonators and following the Chebychev model, we have designed and fabricated superconducting filters with a centre frequency of 2.2 GHz and a bandwidth of 5 MHz. The measured unloaded Q-factor of the resonator fabricated on LaAlO3 using YBCO thin film is 47,000 at 60 K. prototype filters with three and four poles have been realized by using Nb thin films. The measured performances do not show appreciable degradations Lip to 10 dBm. (C) 2002 Wiley Periodicals. Inc.