Analogue Electronics Exam - Summer 2006 - Electronic Engineering, Exams of Digital & Analog Electronics

Download Analogue Electronics Exam - Summer 2006 - Electronic Engineering and more Exams Digital & Analog Electronics in PDF only on Docsity! DLX2 Summer 2006 Analogue Electronics Page 1 of 4 Cork Institute of Technology Bachelor of Engineering (Honours) in Electronic Engineering – Stage 2 (NFQ – Level 8) Summer 2006 Analogue Electronics (Time: 3 Hours) Answer any 5 questions. Examiners : Mr. P. Collins All questions carry equal marks Mr. M. Cranitch Prof. G. Hurley Dr. S. Foley Q1. a) Define the small-signal parameters ‘re’ and ‘β’ for a bipolar junction transistor. [2 marks] b) Derive expressions for the voltage gain , circuit input impedance and circuit output impedance of a common emitter amplifier. The amplifier has a load of RL and has no capacitor across the emitter resistor RE. Include a diagram of the small signal equivalent circuit as part of the derivation. [8 marks] c) For the circuit shown in fig Q1, VCC = 15V, R1 = 33kΩ , R2 = 10kΩ , RC = 940Ω , RE = 330Ω , RL=2.2kΩ and β = 200. Calculate the voltage gain , the current gain , the circuit input impedance and the circuit output impedance. [10 marks] DLX2 Summer 2006 Analogue Electronics Page 2 of 4 Vin Vout RC VCC R1 R2 RE RL C1 C2 Fig Q1. Q2. a) Explain the term ‘small-signal’ operation as applied to the analysis of amplifier circuits. [4 marks] b) Define the parameters gm , rd and µ in the case of a field effect transistor. [6 marks] c) Derive expressions for the voltage gain and output impedance of a common source amplifier. [4 marks] d) The FET shown in fig Q2 has gm = 4.2mS and µ = 410. Determine the voltage gain, input impedance and output impedance of the circuit. [6 marks] Fig Q2.