Radiation Effects on the Microwave Properties of GaAs MESFETs.
Abstract
The effect of fast neutron and gamma irradiation on the electrical characteristics of low noise microwave GaAs MESFET amplifiers has been evaluated. The microwave amplifiers were realized on alumina microstrip using commercial devices mounted in a common source configuration. The changes in the noise figure and amplifier gain at S- and X-band were determined for neutron fluences between 3 x 10 to the 12th power to 1 x 10 to the 15th power n/sq cm and for a gamma dose of 2 x 10 to the 7th power rads (Si). The noise figure starts to be affected at 10 to the 14th power n/sq cm and a large deterioration is observed at 1 x 10 to the 15th power n/sq cm. The increase in noise figure is related to the decrease in transconductance and increase in the parasitic source resistance. The decrease in the amplifier gain at the high neutron fluence is due to a deterioration of the transconductance, source resistance and change in the gate to source and gate to drain capacitances. The low frequency noise increases with neutron radiation but not with gamma-radiation. The low frequency noise appears not to be correlated with the microwave noise. Gamma irradiation increases the noise figure at a dose of 2 x 10 to the 7th power rads (Si) without affecting the signal characteristics of the device. It appears that Gamma-radiation produces levels which respond at microwave frequencies.
Document Details
- Document Type
- Technical Report
- Publication Date
- Jun 01, 1980
- Accession Number
- ADA089410
Entities
People
- Jose M. Borrego
- Kevin G. Rochford
- Ronald J. Gutmann
- Sanjay B. Moghe
Organizations
- Rensselaer Polytechnic Institute