Broadband millimetric semiconductor junction circulators at 77 K

Broadband circulation at millimetric frequencies is currently unavailable. However on utilising the gyrotropic behaviour of the magnetised semiconductor this appears possible. Low-loss theoretical results are presented which suggest GaAs and InSb circulators are feasible with bandwidths greater than an octave and operating up to 125 GHz at a temperature of 77 K.