Superconducting integrated receiver for TELIS

TELIS (Terahertz and submm Limb Sounder) is a cooperative European project to develop a three-channel heterodyne balloon-based spectrometer for measuring a variety of atmospheric constituents within the lower stratosphere. The 600-650GHz channel is based on a phase-locked Superconducting Integrated Receiver (SIR). SIR is the on-chip combination of a low-noise SIS mixer with quasioptical antenna, a superconducting Flux Flow Oscillator (FFO) acting as Local Oscillator (LO) and an SIS harmonic mixer (HM) for FFO phase locking. A number of new solutions was implemented in the new generation of SIR chips. To achieve the wide-band performance of the spectrometer, a side-feed twin-SIS mixer with 0.8 μm² junctions integrated with a double-dipole (or double-slot) antenna is used. A Fourier transform spectrometer (FTS) test demonstrated a possibility to obtain the required instantaneous bandwidth for the SIS mixer. To ensure the autonomous operation of the phase-locked SIR on the balloon a number of approaches for the PLL SIR automatic control have been developed.