Phase-locked loop with power scaling prescaler and multimode bandwidth loop filter

Abstract

The invention discloses a phase-locked loop with a power scaling prescaler and a multimode bandwidth loop filter. The prescaler of the phase-locked loop is formed by a plurality of scalers in cascade connection, and transistor sizes of the scaler in each stage are different, so current of the scaler in each stage is in direct proportion with frequency of the scaler in each stage so as to realize power optimization of the prescaler; and the loop filter of the phase-locked loop performs bandwidth dynamic switching by adopting loop filters in different bandwidths. The phase-locked loop is used for a semiduplex radio frequency transceiver, when the transceiver is in a receiving mode, the phase-locked loop is set in a low-bandwidth mode to reduce in-band noise and stray of the phase-locked loop and improve the selectivity of adjacent step channels of the receiver; when the transceiver is in a transmitting mode, the phase-locked loop is set in a medium bandwidth mode to realize normal transmission of frequency modulation data, reduce error vector magnitude of the transmitter, and improve the rejection ratio of adjacent step channels; and when the phase-locked loop is in an establishing state, the transceiver is set in a high bandwidth mode to accelerate the establishing speed of the phase-locked loop.

Description

technical field [0001] The invention relates to the technical field of phase-locked loops, in particular to a phase-locked loop with a power consumption scaling prescaler and a multi-mode bandwidth loop filter. The phase-locked loop is especially suitable for half-duplex radio frequency transceivers. Background technique [0002] In the currently commonly used charge pump phase-locked loop, the power consumption of the prescaler usually accounts for most of the power consumption of the entire phase-locked loop due to high operating frequency, complex structure, and large parasitic influence. The power consumption of the frequency converter is very important to reduce the power consumption of the whole phase-locked loop. In addition, the bandwidth of the loop filter in the phase-locked loop determines the establishment time and response speed of the phase-locked loop, and affects the noise distribution and spurs of the phase-locked loop. [0003] For the prescaler, the tradi...

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Problems solved by technology

[0005] The technical problem to be solved by the present invention is to provide a phase-locked loop with a power scaling prescaler and a multi-mode bandwidth loop filter to overcome the inability to effectively reduce the power consumption of the prescaler and the loop filter in the prior art. Fixed defect of filter bandwidth mode

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