VOLTAGE CONTROLLED OSCILLATOR WITH MULTIPLE BANDWIDTH

摘要

PURPOSE: A voltage controlled oscillator with multiple bandwidth is provided to reduce the manufacturing cost and the size of components by controlling a connection of a coil or a capacitor constructing a resonance circuit through a switching device. CONSTITUTION: A resonance circuit is comprised of a variable capacitance diode(D1) connected to an input voltage terminal, a first coil(L1) connected in parallel to the variable capacitance diode(D1), and a frequency control device connected in parallel to the first coil(L1). The resonance circuit receives a voltage signal from an external to generate an output signal of a resonance frequency. A pin diode is formed between an end of the frequency control device of the resonance circuit and a ground terminal and controls a connection of the frequency control device to vary a frequency bandwidth of the output signal. An amplifying circuit(10) amplifies the output signal. The frequency control device is a second coil(L2).