发明名称 Method and apparatus for frequency synthesis in direct-conversion transmitters
摘要 A method and apparatus for direct-conversion transmission generates a first frequency signal that is non-harmonically related to a transmit frequency signal, divides the first frequency signal to obtain a mixing frequency signal, divides the first frequency signal to obtain an intermediate frequency reference signal, generates the transmit frequency signal by using the mixing frequency signal to downconvert the transmit frequency signal into an intermediate frequency feedback signal, and phase-locks the intermediate frequency feedback signal to the intermediate frequency reference signal. The transmit frequency signal may be phase modulated, and may serve as an input to a saturated-mode power amplifier that can be configured for corresponding amplitude modulation. Alternatively, the un-modulated transmit frequency signal serves as the carrier signal input to a quadrature modulator, which imparts I/Q modulations to it, thereby producing a modulated carrier signal for input to a linear power amplifier.
申请公布号 US2007019109(A1) 申请公布日期 2007.01.25
申请号 US20050186380 申请日期 2005.07.21
申请人 LOMBARDI FRANK T;FREED JOHN G;ISBERG MARTIN 发明人 LOMBARDI FRANK T.;FREED JOHN G.;ISBERG MARTIN
分类号 H03L7/00 主分类号 H03L7/00
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