Circuit Design of Classical Stages with Bandwidth Enhancement Technique

The circuit design features of classical stages (common-base (CB), common-emitter (CE)) and voltage follower with a capacitive load with bandwidth enhancement technique based on the effect of the mutual compensation of the parasitic impedances are considered. The technique is based on introduction of special circuits of active frequency correction, such as current and voltage followers. The advantage of such technique is limited by frequency range of these followers, which can be implemented on base of simple structure with high transition frequency. The mathematical conditions of bandwidth enhancement technique are also considered. Several wideband amplifiers based on proposed technique are shown. The simulation results show that bandwidth increased for 2.41 times without degradation of voltage gain in case of circuit on base of common-base stage, 2.1 times in case of differential circuit on base of common-emitter stage and 2.42 times in case of voltage follower´s circuit that based on common-collector circuit.