Title :
A high-frequency GaAs transductance circuit and its applications
Author :
Wu, Pan ; Schaumann, Roy
Author_Institution :
Dept. of Electr. & Comput. Eng., Portland State Univ., OR, USA
Abstract :
The design of a high-speed, linear, tunable operational transconductance amplifier (OTA) with 1 μm GaAs depletion-mode MESFETs is described. Gain-enhancement techniques are used for obtaining high output impedance. In order to achieve a large tuning range with stable DC bias, a combination of digital and analog tuning is used. Diode-only level-shifting stages and bypass capacitors across the diodes are used to optimize the AC response. Emitter degeneration along with small compensation capacitors are used to achieve less than one percent nonlinearity error within a ±0.4 V input range, and to reduce the total excess phase shift. Applications of the OTA in the GHz range are presented as examples
Keywords :
III-V semiconductors; Schottky gate field effect transistors; field effect integrated circuits; gallium arsenide; high-frequency amplifiers; linear integrated circuits; microwave amplifiers; operational amplifiers; radiofrequency amplifiers; tuning; 1 micron; AC response optimisation; GHz range; GaAs; analog tuning; bypass capacitors; compensation capacitors; depletion-mode MESFETs; digital tuning; diode-only level shifting stages; gain enhancement; high-frequency; linear tunable OTA; operational transconductance amplifier; transductance circuit; Capacitors; Circuits; Differential equations; Gallium arsenide; Impedance; Linearity; MESFETs; SPICE; Threshold voltage; Variable structure systems;
Conference_Titel :
Circuits and Systems, 1990., IEEE International Symposium on
Conference_Location :
New Orleans, LA
DOI :
10.1109/ISCAS.1990.112663
