ON THE DESIGN AND MEASUREMENT OF A 2.5THz WAVEGUIDE MDCER

The usefulness of waveguide circuits at frequencies as high as 3THz has now been demonstrated culminating in the realisation of a 2.5THz waveguide mixer implementing Schottky diodes. For waveguide devices to be optimised at these frequencies it has been necessary to modify the design of the waveguide mount paying particular consideration to areas such as ease of assembly, simplification of machining, reliability and fast adjustment of the RF circuit. This paper discusses the detailed design and associated RF performance of a new 2.5THz waveguide mixer mount that makes use of the following: an ultrasonically bonded RF circuit, a non-contacting backshort and part fabricated waveguide. All of these features are aimed at determining the optimum impedance required by the Schottky diode used and thus provide a more ideal circuit in which to place it.