| 摘要 |
A method and apparatus for frequency synthesis in a transceiver are based on providing a primary frequency synthesizer configured to synthesize a receiver frequency signal from a receiver reference frequency signal, and providing an offset frequency synthesizer configured to synthesize a transmitter frequency signal from the receiver frequency signal using fractional-N division, which allows it to operate at an intermediate frequency that is a non-integer multiple of the receiver frequency signal. That arrangement enables non-integer duplex frequency distances between desired receive and transmit frequencies. The primary frequency synthesizer also may be operated as a fractional-N frequency synthesizer, meaning that the receiver frequency signal may have a non-integer relationship to the receiver reference frequency signal. Configuring the primary and offset frequency synthesizers to operate with fractional-N frequency synthesis allows independent frequency tuning/optimization of the primary and secondary frequency synthesizers.
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