Modified Colpitts oscillator for driving an antenna coil and generating a clock signal

An oscillator circuit consisting of:

• a first transistor;
• a second transistor coupled to the first transistor;
• the first and second transistors being operatively coupled to a supply voltage;
• an LC circuit coupled to provide positive feedback between the first and second transistors, the LC circuit consisting of first and second capacitors connected in series forming a capacitive divider network, which capacitive divider network is connected in parallel with a coil having an inductance, the value of the inductance and the value of capacitance of the first and second capacitors in series determining a resonant frequency at which the oscillator circuit oscillates, the capacitive divider network providing a low impedance feedback via the second transistor to the first transistor,
• the first and second transistors each comprising bipolar transistors, each having a base, a collector and an emitter, and wherein the emitter of the second transistor is connected to the emitter of the first transistor via a first resistor, and wherein the LC circuit is coupled between the collector of the first transistor and the base of the second transistor, and
• a bias network comprising a third capacitor and a second resistor coupled to the first transistor;
• whereby the oscillator circuit produces a high Q, low distortion output signal in the coil.