Radio-Frequency Heating of GaAs and SiC Photoconductive Switch for High-Power Applications
- Resource Type
- Periodical
- Authors
- Gunda, R.; Gleason, D.S.; Kelkar, K.; Kirawanich, P.; Nunnally, W.C.; Islam, N.E.
- Source
- IEEE Transactions on Plasma Science IEEE Trans. Plasma Sci. Plasma Science, IEEE Transactions on. 34(5):1697-1701 Oct, 2006
- Subject
- Engineered Materials, Dielectrics and Plasmas
Fields, Waves and Electromagnetics
Switches
Radio frequency
Heating
Gallium arsenide
Silicon carbide
Photoconductivity
Thermal conductivity
Temperature
Contacts
Microwave generation
High-power microwaves (HPMs)
photoconductive semiconductor switches (PCSSs)
radio-frequency (RF) heating effects
- Language
- ISSN
- 0093-3813
1939-9375
The response of a nonlinear opposed contact GaAs photoconductive switch, which is used in high-power microwave generation, was studied for high-power radio-frequency heating effects and compared with a linear-mode SiC switch. Current-controlled negative resistivity behavior was observed at elevated temperature in both cases. Better thermal conductivity and the absence of a heat sink result in a faster temperature increase and in local thermal carrier generation in SiC. Negative resistivity characteristics leading to unstable filamentation and thermal runaway are therefore more severe and occur at a lower bias in SiC as compared with a GaAs switch. To counter such effects, mechanisms to remove excess heat in switches in high-power application must be devised.