NEW DESIGNS FOR ANTENNA-COUPLED SUPERCONDUCTING BOLOMETERS

We propose a novel antenna-coupled low T(c) supereonducting bolometer which makes use of the thermal boundary resistance and the trapping of quasiparticles at metal-superconducting interfaces. A thin strip of superconductor, whose temperature is regulated at the midpoint of its resistive transition, serves both as a resistive load to thermalize the infrared current from the antenna and as a thermometer to measure the resulting temperature rise. Calculations give a noise equivalent power (NEP) almost-equal-to 7 X 10(-16) T5/2 WHz-1/2 and a time constant tau-almost-equal-to 10(-8) T-2 s for a 2 X 2-mu-m2 thermometer area at temperature T (K). Designs for efficient on-chip rf matching and filter networks with well-defined bandpasses are presented. These detectors can be used to make frequency-multiplexed array receivers for astronomical observations at near millimeter wavelengths.