A fully integrated GMSK modulator using BiCMOS /spl Sigma/-/spl Delta/ frequency synthesizer with automatic loop gain calibration

摘要

A 2.7 V 16 mA GMSK modulator using a /spl Sigma/-/spl Delta/ frequency synthesizer with automatic loop gain calibration is implemented on a 3.2 mm/sup 2/ die area using a 0.35 /spl mu/m BiCMOS process. It meets the GSM transmit spectral mask specification and achieves a close-in phase noise of -90 dBc/Hz and spurious noise level of -75 dBc/Hz without modulation.