Frequency synthesizer for cellular transmitters demands low phase-noise both in-band and out-of-band. The first is necessary to implement wideband modulations (e.g. WCDMA), while the second to satisfy the challenging emission mask of GSM. Moreover a low level of fractional spurs must be ensured. The paper describes the first dither-less ADPLL capable to satisfy all these requirements. These results are achieved exploiting a highly linear 2- dimension Vernier TDC and a very fine frequency resolution DCO. Both building blocks heavily rely on digital calibration techniques to precisely and efficiently implement two-point modulation and spur cancellation in the presence of many implementation impairments.
A dither-less all digital PLL for cellular transmitters2011 IEEE Custom Integrated Circuits Conference (CICC)
VERCESI, LUCA;LISCIDINI, ANTONIO;CASTELLO, RINALDO
2011-01-01
Abstract
Frequency synthesizer for cellular transmitters demands low phase-noise both in-band and out-of-band. The first is necessary to implement wideband modulations (e.g. WCDMA), while the second to satisfy the challenging emission mask of GSM. Moreover a low level of fractional spurs must be ensured. The paper describes the first dither-less ADPLL capable to satisfy all these requirements. These results are achieved exploiting a highly linear 2- dimension Vernier TDC and a very fine frequency resolution DCO. Both building blocks heavily rely on digital calibration techniques to precisely and efficiently implement two-point modulation and spur cancellation in the presence of many implementation impairments.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
