| 摘要 |
PROBLEM TO BE SOLVED: To provide a voltage-controlled oscillator whose frequency variation range can be widened without deteriorating a phase noise characteristic nor requiring a large occupation area. SOLUTION: A control voltage CTRL for controlling the oscillation frequency (f) of the voltage-controlled oscillator CTRL is supplied to the connection point O1 between varactor diodes D1 and D2. Connection points O2 and O3 are connected to a source voltage Vcc through switching transistors S4 and S6. The relation between the oscillation frequency (f) and the control voltage CTRL is switched according to whether the source voltage Vcc is applied to the connection point O2. Switching transistors S4 to S7 are arranged outside a loop of a resonance circuit composed of the inductor 13 and the varactor diode D1 to D6. COPYRIGHT: (C)2004,JPO
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