Design of Subharmonically Pumped Schottky Mixers for Submillimetre-wave Applications

This work represents a further step to establish a physical numerical CAD tool for the design of Schottky-diode based MMIC circuits for millimetre-wave and terahertz applications. This software has shown very good capabilities for the design and optimization of Schottky multipliers and fundamental mixers with good agreement with measurements. The tool allows the concurrent optimization of the semiconductor device and the external circuit. The additional functionality presented in this paper consists of the design of subharmonically-pumped (SHP) GaAs Schottky diode mixers. Thus, a realistic prediction regarding LO power requirements, influence of parasitics, optimum input and output matching networks and mixer performance can be obtained prior to fabrication avoiding costly redesigns. A 400 GHz antiparallel-diode pair SHP mixer have been designed and optimized. State-of-the-art conversion losses are predicted for this SHP mixer