Modeling of attenuator structures on field effect transistors with minimal phase shift at attenuation regulation

Abstract

Controlled absorbing attenuators on Schottky-gate FETs: T-circuit, T-shaped bridge circuit and transistor attenuator in the mode with controlled slope of voltage-current characteristic have been considered. Attenuator phase-frequency characteristics were modeled. The main difference of the circuits from the known ones consists in introduction of equalizers that conditions broadband feature and large attenuation range where minimum of the phase shift is achieved at regulation. As a result, the optimal parameters of adjusting circuits in attenuators are founded. It is shown that the least phase shift is provided in attenuators on transistor with controlled volt-ampere characteristic steepness. The comparative estimation of the considered base structures was given.