Study on integrated transmission line ΣΔ modulators

The feasibility and design guidelines for implementing integrated transmission-line based Sigma Delta modulators (ITLSDMs) have been studied. By a systematic design methodology for wireless frequency standards, the practical issues of realizing ITLSDMs such as different semiconductor technologies, performance, area and power consumption have been addressed. Having compared the different technologies and types of transmission lines (TLs), a typical 4th order bandpass SDM (BPSDM) as well as a 2nd order lowpass one (LPSDM) for a sampling frequency (f_s) of 10GHz and a bandwidth (BW) of 78MHz have been simulated behaviorally to obtain the minimum circuit requirements for each architecture. An area estimation approach and an optimum realization method are finally proposed which lead to reduced chip area while keeping the performance constant.