Title :
The influence of transit-time effects on the optimum design and maximum oscillation frequency of quantum well oscillators
Author :
Kesan, Vijay P. ; Neikirk, Dean P. ; Blakey, Peter A. ; Streetman, Ben G. ; Linton, Thomas D., Jr.
Author_Institution :
Microelectron. Res. Center, Texas Univ., Austin, TX, USA
fDate :
4/1/1988 12:00:00 AM
Abstract :
A small-signal analysis of quantum-well oscillators is presented. The analysis includes the transit-time effects associated with a depleted spacer layer outside the quantum well. These transit-time effects are found to dominate device characteristics and to lead to dramatic increases in achievable negative resistance. Closed-form expressions are derived for specific negative resistance and cutoff frequency, and a universal curve relating maximum transit-time negative resistance, quantum-well current-voltage characteristics, and frequency is found. Design considerations to maximize the oscillation frequency threshold are discussed. The analysis also shows that the effective limit on the maximum oscillation frequency of practical quantum-well oscillators is determined by a combination of impedance matching constraints and minimum-achievable contact resistance
Keywords :
microwave oscillators; semiconductor junctions; solid-state microwave devices; transit time devices; cutoff frequency; depleted spacer layer; device characteristics; impedance matching constraints; increases in achievable negative resistance; maximum oscillation frequency; maximum transit-time negative resistance; microwave oscillators; minimum-achievable contact resistance; optimum design; oscillation frequency threshold; quantum well oscillators; quantum-well current-voltage characteristics; small-signal analysis; transit-time effects; universal curve; Anodes; Closed-form solution; Current-voltage characteristics; Diodes; Frequency estimation; Impedance matching; Millimeter wave circuits; Oscillators; Power engineering computing; Tunneling;
Journal_Title :
Electron Devices, IEEE Transactions on
