YBaCuO HEB hot-spot model with non-uniform RF power absorption: THz mixing frequency-dependent performance

Abstract

High-T C superconductor (YBaCuO) hot electron bolometers (HEB) are promising THz mixers due to the large predicted bandwidth and the low local oscillator (LO) power requirement. Recently, we introduced the hot-spot model, initially dedicated to low-T C NbN devices, to predict YBaCuO mixer performance. Major improvements to the model have been introduced: i) local description of the power absorption along the HEB constriction, ii) THz dependence of the resistive transition, iii) impedance matching between the THz antenna and the constriction. Mixer noise temperature T N and conversion gain G were predicted up to 2.5 THz. For instance, T N = 2700 K (DSB) and G = −13 dB are obtained with 9 μW of LO power at 1 THz.