Design of superheterodyne radiometer as ECE diagnostic for electron temperature profile measurement in SST-1

This paper presents the design of an eight-channel W band radiometer as an electron cyclotron resonance (ECE) diagnostic to measure the electron temperature for phase I (Bt0 = 1.5 T) operation of SST-1. A double-sideband (DSB) mixer cum power divider method is used to cover the full range of ECE frequencies. The noise figure, sensitivity and expected output signal of the radiometer are estimated and a calibration technique is discussed. A time resolution of 5 μs and a spatial resolution of 0.6 cm for 2fce = 70 GHz are achieved by this radiometer.