Abstract
A fully integrated tunable 4th-order multi-feedback bandpass delta-sigma modulator (BPDSM) fabricated in 0.25um SiGe BiCMOS is presented. The input frequency can be tuned from 945MHz to 988MHz at 2.4GHz fixed clock frequency. This modulator dissipates 110mA from 3.3V power supply. The peak signal-to-noise-ratio (SNR) of sinewave input is 41.1dB in 10MHz bandwidth and error vector magnitude (EVM) of 64QAM long term evolution (LTE) downlink is 3.16%, 3.59%, and 3.65% at different carrier frequencies.
