70-MHz IF 10-MHz bandwidth bandpass UpsigmaUpdelta modulator for WCDMA applications

A MASH bandpass $UpsigmaUpdelta$ modulator for wide-band code division multiple access (WCDMA) applications is presented. The signal bandwidth of the proposed modulator is 10?MHz centered around an intermediate frequency (IF) of 70.5?MHz. Two two-path second-order bandpass $UpsigmaUpdelta$ modulators make the MASH architecture, which realizes a noise transfer function with four couples of complex conjugate zeros. The proposed circuit, fabricated with a 0.18???m CMOS technology, uses a sampling frequency of 180?MHz to obtain a resolution of about 12?bits in the 10?MHz bandwidth around the IF. The measured modulator power consumption is 95?mW with a supply voltage of 1.8?V. The achieved figure-of-merit (FoM _BP ) is 0.37?pJ/conversion-level.