Development and Testing of a Receiver at 230 GHz

A superhetrodyne receiver operating at 230 GHz has been developed and tested. The hybrid mixer consists of a Schottky barrier diode in a rectangular waveguide and a stripline circuit whose performance was optimized using low frequency scaling techniques. Ultra-low capacitance, low-noise Schottky barrier diodes were developed for use in the mixer. The local oscillator signal is provided by a frequency doubler pumped by a 115 GHz klystron. The output of the doubler is coupled into the mixer using a cavity. The IF amplifier is a 1.4 GHz parametric amplifier with a noise figure of 0.8 dB. The total double sideband noise figure of the receiver is 13.4 dB corresponding to a noise temperature of 6000 K.