Superconducting Integrated Submm Wave Receivers

The concept of the fully Superconducting Integrated Receiver (SIR) has been developed and experimentally demonstrated. The single-chip submm wave receiver includes a planar antenna integrated with a SIS mixer, which is pumped by an internal superconducting Flux Flow Oscillator (FFO) as local oscillator (LO). A DSB noise temperature below 100 K has been demonstrated around 500 GHz. Heterodyne measurements have shown that the instantaneous bandwidth of the receiver is 15 – 20 % which meets the requirements of practical applications. The double-dipole lens-antenna SIS mixer has an antenna beam ≈ f/9 with sidelobes below- 16 dB. This enables an efficient coupling of the SIR to the telescope antenna. With the FFO phase locked in the frequency range 270- 440 GHz a linewidth as low as 1 Hz has been measured relative to a reference oscillator. A compact array of 9 SIRs has been developed and tested. Each pixel contains an internally pumped receiver chip, which is mounted on the back of an elliptical silicon lens. A noise temperature of about 150 K has been measured at 500 GHz using the internal FFO for the imaging array of Integrated Receivers