Investigation of the effect of stage cascade on amplifier circuits in a common emitter configuration using bypass and non-bypass capacitors

Abstract

This research investigates the effect of stage cascade on amplifier circuits using transistor in the common emitter configuration. A two-stage amplifier was constructed and its performance was analyzed accordingly. The voltage gain of the amplifier with bypass capacitor is 16.09dB and that non-bypass capacitor is 15.98dB with bandwidths of 600Hz and 800Hz respectively. The current gain of the circuit is 14.2dB. Input and output resistances of the circuit are 333.3Ω and 415.58Ω respectively. The power gain of the constructed amplifier/circuit is 15.16dB. The overall voltage gain is 16.09dB±0.11dB which shows that the theory on multistage amplification is satisfied, since the overall gain is a product of the individual stage gain. The result shows that cascaded amplifier with by-pass capacitors has a better amplification than those without by-pass capacitors as a result amplification is increased and distortion is also increased; waveform was noisier as against the single stage but the input waveform was preserved.