Bandpass Continuous-Time Delta-Sigma Modulator forWireless Receiver IC

Bandpass ADC is well known to be adopted in thenarrowband receiver design in order to reduce the systemcomplexity, increase integration and improve performance bydigitizing the bandpass signal directly without prior conversionto baseband. A fully differential feedforward fourth-ordercontinuous-time bandpass delta-sigma modulator is presented.The proposed single-bit modulator can receive 172.8kHz IFsignals by using an oversampling clock frequency of 5.53MHzwith an OSR of 128. Simulated result showing that dynamicrange of 78dB within bandwidth of 21.6kHz is achieved and thecurrent consumption is around 1.2mA at 1.5V power supply.The design had been implemented in 0.13μm 1P6M CMOSprocess with MIM capacitors.