A broadband 440–590 GHz receiver

The development and testing of a broadband 440-590 GHz receiver for use with THz radiometers is presented. The receiver is based on a broadband subharmonic mixer developed at VDI, which has a mixer noise temperature ranging from 1500-2500 K (DSB) over the full waveguide band from 400-600 GHz, while requiring an LO power of only 2-3 mW. The local oscillator consists of a JPL WR-10 broadband amplifier driving a VDI tripler. Excellent performance was achieved without any tuning.