| 摘要 |
PURPOSE: A dual band voltage control oscillation circuit is provided to select and oscillate low and high band frequencies using one voltage control oscillator without prior two oscillation circuits, thereby simplifying the oscillation circuit, realizing compact size and reducing costs. CONSTITUTION: A dual band voltage control oscillation circuit comprises a band select circuit unit(32), a resonance circuit unit(31) and an oscillation circuit unit(35). The band select circuit unit(32) varies capacitance in accordance with a band select voltage(Vsel) having two voltage levels(high/low). The resonance circuit unit(31) and an oscillation circuit unit(35) resonates the frequency decided by capacitance micro-controlled by a tuning voltage(VT), inductance and the capacitance of the unit(32). The oscillation circuit unit(35) oscillates the resonance frequency of the unit(31).
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