A design analysis of imaging radiometer with antenna-coupled transition-edge sensors

A transition-edge sensor multi-layer film absorber (Mo/Cu, T c = 0.3 –0.4 K) is assumed to connect the leads of the antenna made from Nb. The RF current from antenna is the source of hot electrons within the absorber; the heat escape to the substrate is limited by the low electron–phonon interaction at low temperature. The Andreev electron-reflection effect can prevent the heat leak to the antenna terminals. To build an imaging array, the multiplexing procedure via method of projections allows for readout from columns or rows, not from individual pixels, so the number of leads can be reduced to N+M for N × M double-polarized array. The full-time signal accumulation is effective for all pixels employing a polarization separating cross-slot antenna. Microstrip and coplanar waveguides are used in the matching circuit of the 9-pixel array. Wide-band signal coupling is simulated for a 5- Ω absorber at 600 GHz.