COMPOSITION APPARATUS OF DUAL BAND PHASE ASYNCHRONOUS LOOP

摘要

PURPOSE: A composition apparatus of dual band phase asynchronous loop is provided to improve the quality of cellular phone by controlling stable frequency oscillation and by improving noise characteristic. CONSTITUTION: The first voltage controlled oscillator(21) offer oscillation frequency for PCS. The second voltage controlled oscillator offer oscillation frequency for DCS. A loop filter offer output voltage of a phase asynchronous loop(23) to the each voltage controlled oscillator. The first, second capacitor(C1)(C2) get improved harmonic characteristic with connecting between each output terminal of the first, second voltage controlled oscillator(21)(22) and frequency input terminal of phase asynchronous, and get improved characteristic of noise for noise creating on transmission/reception to intercept path taking feedback through the phase asynchronous loop(23).