Novel K-band tunable microstrip bandpass filter using a thin film HTS/ferroelectric/dielectric multilayer configuration
IEEE MTT-S International Microwave Symposium Digest
We report on YBCO/strontium titanate (STO) thin film K-band tunable bandpass filters on lanthanum aluminate substrates. The 2 pole filters were designed for a center frequency of 19 GHz and 4% bandwidth. Tunability is achieved through the non-linear dc electric field dependence of the relative dielectric constant of STO (εrSTO). Center frequency shifts greater than 2 GHz were obtained at a 400 V bipolar dc bias at temperatures below 77 K, with minimal degradation in the insertion loss of the filters.
Original Publication Date
Subramanyam, G.; Van Keuls, F.; and Miranda, F. A., "Novel K-band tunable microstrip bandpass filter using a thin film HTS/ferroelectric/dielectric multilayer configuration" (1998). Faculty Publications. 3947.