Integrated transmission lines for complementary cross-coupled bandpass filters in ΣΔ modulators

Abstract

In this paper, the properties of various types of transmission lines (TLs) intended for an integrated RF TL based sigma delta modulator (ITLSDM) are extracted. The EM simulator is used to achieve accurate models for TLs in a 180nm CMOS technology. The effects of TL parameters are compared and studied in order to achieve the guidelines, which save the area and power consumption of the modulator. The results are verified with an architecture, which is based on complementary cross-coupled bandpass filter (C-BPF) with an auxiliary negative transconductance (ANG). This filter is employed in a 9.6GHz 4th order fs/4 bandpass SDM tuned at a center frequency of 2.4GHz.