Hybrid semiconductive/high-temperature superconductive tunable preselector

HTSC lumped element filters with GaAs varactor tuning, P-HEMT LNAs with HTSC lumped element matching and a GaAs MMIC SP4T switch with integrated decoding are described for use in a broadband cryogenic preselector operating from 200 MHz to 2 GHz. The filters tune over their respective sub-bands and have insertion losses ranging from 2 to 14 dB. The sub-band LNAs have from 8.5 to 11.5 dB of gain, noise figures under 1.5 dB and input return losses greater than 20 dB. The SP4T MMIC multiplexing switch has under 0.5 dB insertion loss, isolation in excess of 30 dB and 10/90% switching speed under 100 nsec. These components are designed to be assembled into a 30 cubic centimeter electronically tunable four-channel proof-of-principal preselector operating over portions of the 200 MHz to 2 GHz band.