Abstract:
An oscillator includes a transistor, a first bias resistor connected between the base of the transistor and a power input terminal, and a second bias resistor connected between the base of the transistor and a control-voltage input terminal. When the control-voltage input terminal is grounded, the bias voltage at the base of the transistor is below a predetermined threshold, thus causing the oscillator to stop oscillation. When the control-voltage input terminal is open, the bias voltage at the base of the transistor is above the threshold, thus causing the oscillator to start oscillation.
Abstract:
A high-frequency superposing module for driving a laser diode includes an oscillating circuit and an impedance matching circuit. The impedance matching circuit includes a capacitor connected in series between the emitter of a transistor and the terminal through which a laser-diode drive signal is output; and a capacitor connected in parallel between the drive-signal output terminal and the ground. The oscillating circuit includes an inductor serving as a choke coil connected between the drive-signal output terminal and the collector of the transistor, thus allowing the drive-signal output terminal to serve as a power input terminal for the oscillating circuit.