A Hartley oscillator

Exercise 10.2 A Hartley oscillator

The figure below shows the circuit schematic of a Hartley oscillator. Transistor T has $βfe = 99$ and is ideal otherwise. Furthermore, set $C = 1 nF$ and $L_{1} = 1 mH$ . The current through $R_{B 1}$ and $R_{B 2}$ may be neglected.

pict

a): What is the function of $C_{0}$ and what can you say about its size?
b): The transistor is set at $I_{C} = 5 mA$ ; calculate the $g_{m}$ of the transistor.
c): Draw a small-signal equivalent of this oscillator circuit.
d): Formulate the oscillation condition and derive an expression for the oscillation frequency.
e): Derive an expression for the value of $L_{2}$ to obtain stable oscillation at the (radian) frequency derived in the previous question.

[prev] [prev-tail] [front] [up]