A very wide-band microwave MESFET mixer using the distributed mixing principle
Abstract
A new theory of distributed (travelling-wave) mixing is presented. A closed-form expression for the conversion gain is derived. Subsequently, the expression is reduced to a very simple form when the mixer approaches the ideal lossless case. A simplified nonlinear model of a GaAs MESFET is also described. Design criteria and considerations are presented. The relative contributions made by circuit parasitics to the conversion gain-bandwidth product are also examined. Experimental verification on a two-section design is described. It exhibits around 4 dB of conversion loss over the signal frequency band from 2 GHz to the cutoff at 10 GHz for an IF of 1.5 GHz. Expeerimental results obtained corroborate the theoretical predictions. Better performance is expected if more sections are employed.
- Publication:
-
IEEE Transactions on Microwave Theory Techniques
- Pub Date:
- December 1985
- DOI:
- Bibcode:
- 1985ITMTT..33.1470T
- Keywords:
-
- Broadband;
- Field Effect Transistors;
- Microwave Circuits;
- Mixing Circuits;
- Circuit Diagrams;
- Design Analysis;
- Equivalent Circuits;
- Gallium Arsenides;
- Schottky Diodes;
- Wave Attenuation;
- Electronics and Electrical Engineering