F.E.T. mixer with the drain L.O. injection
Abstract
Results are presented for a study intended to evaluate the performance of a FET 6/4 GHz frequency downconverter with drain LO injection, designed for communication satellite transponders. A 2.225 GHz LO signal is used to modulate the FET drain resistance between a low value corresponding to unsaturated drain current flow and a high saturated value. Transconductance is also modulated. The discussion covers the conversion gain versus LO power and the variation of conversion gain and noise temperature with the ambient temperature. Conversion gains up to 4.7 dB with 3.9 dB noise figure are observed. A gain increase of 2.4 dB and a noise-figure decrease of 1.8 dB are measured upon cooling to 200 K. The lowest noise performance is achieved with small drain currents.
- Publication:
-
Electronics Letters
- Pub Date:
- September 1976
- DOI:
- 10.1049/el:19760407
- Bibcode:
- 1976ElL....12..536B
- Keywords:
-
- Down-Converters;
- Field Effect Transistors;
- Frequency Converters;
- Microwave Oscillators;
- Mixing Circuits;
- Signal Mixing;
- Communication Satellites;
- Low Noise;
- Microwave Circuits;
- Noise Temperature;
- Power Gain;
- Satellite Transmission;
- Transponders;
- Communications and Radar