| 摘要 |
PURPOSE: The transceiver of a portable wireless terminal is provided to maintain the isolation and the efficiency in transmission and reception, by connecting an unequal split in-line power divider to a voltage to the output terminal of a Voltage Controlled Oscillator(VCO) at the frequency synthesizer. CONSTITUTION: A frequency synthesizer(100) includes a phase-locked loop(10), a loop filter(20) and a Voltage Controlled Oscillator(VCO)(30). The phase-locked loop(10) compares a reference frequency with the frequency of a feedback signal, and generates an alternating voltage signal in response to phase difference. The loop filter(20) passes a low band component of the alternating voltage signal from the phase-locked loop(10), and thereby generates the signal with a direct current component. The voltage controlled oscillator(30) generates the signal having a constant transmission intermediate frequency in response to the signal from the loop filter(20).
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