Superconducting Integrated Submillimeter Receiver for TELIS

In this report an overview of the results on the development of a single-chip superconducting integrated receiver for the terahertz limb sounder (TELIS) balloon project intended to measure a variety of stratosphere trace gases is presented. The superconducting integrated receiver (SIR) comprises in one chip a planar antenna integrated with a superconductor-insulator-superconductor (SIS) mixer, a superconducting flux flow oscillator (FFO) acting as local oscillator (LO) and a second SIS harmonic mixer (HM) for FFO phase locking. As a result of the FFO design optimization a free-running linewidth between 9 and 1.5 MHz has been measured in the frequency range 500-710 GHz resulting in phase-locking of 35 to 95% of the FFO power correspondingly. A new generation of the SIR devices with improved FFO performance and optimized interface between FFO and SIS/HM has been developed and comprehensively tested. As a result all required TELIS parameters were demonstrated. Phase-locked FFO operation over entire SIR channel frequency range has been realized, spectral resolution below 1 MHz has been confirmed by gas cell and CW signal measurements. An uncorrected double side band (DSB) noise temperature below 250 K has been measured with the phase-locked FFO. The intermediate frequency bandwidth 4-8 GHz has been realized. To ensure remote operation of the phase-locked SIR several procedures for its automatic computer control have been developed and tested.