Title :
Analysis of microwave characteristics of a double-channel FET employing the velocity-modulation transistor concept
Author :
Maezawa, Koichi ; Mizutani, Takashi
Author_Institution :
NTT LSI Labs., Kanagawa, Japan
fDate :
11/1/1992 12:00:00 AM
Abstract :
The high-frequency characteristics of the double-channel FET employing the velocity modulation concept are calculated using the wave equation method. In order to define Y-parameters, the second gate is connected to the source electrode so that the device has only three terminals. In this case, the effect of velocity modulation takes place only in the high-frequency region. The current gain and the unilateral power gain are obtained from the Y-parameters. The results show that the double-channel structure with high-and low-mobility channels is effective for increasing not the cutoff frequency fT but the maximum frequency of oscillation fmax. At the frequency corresponding to the fmax of a conventional FET, a power gain of about 10 dB can be obtained. The cutoff frequency of the four-terminal double-channel VMT is also discussed
Keywords :
field effect transistors; semiconductor device models; solid-state microwave devices; 10 dB; Y-parameters; current gain; cutoff frequency; double-channel FET; four-terminal double-channel VMT; high-frequency characteristics; high-mobility channel; low-mobility channels; maximum frequency of oscillation; microwave characteristics; power gain; velocity-modulation transistor; wave equation method; Cutoff frequency; Delay effects; Doping; Electrodes; Electrons; Microwave FETs; Microwave transistors; Partial differential equations; Transconductance; Voltage;
Journal_Title :
Electron Devices, IEEE Transactions on
