Anjan Chakravorty

A new high efficiency stacked millimeter-wave transformer is designed and fabricated in 0.18 μm CMOS technology using dual thick metal stack. The proposed configuration allows efficient implementation of two turn stacked transformers, exclusively using top two thick metal layers. Measurements show significant improvements in efficiency, coupling coefficient and current handling when compared to existing two turn stacked transformer configurations. Using the top thick metals substantially increases the current handling while reducing the capacitance to substrate. Further, the proposed transformer exhibits perfect symmetry across both primary and secondary and can be readily converted to a balun.

This study presents the implementation of a millimeter-wave compact bandstop filter (BSF) using the standard 0.18 μm CMOS process. The topology is based on transversal signal interference technique, obtained by connecting two transmission lines with proper characteristic impedances and electrical lengths in parallel. Sharp-rejection characteristics are obtained without using any extra resonators. Moreover, BSF having single-characteristic impedance is analyzed for design simplicity. A compact thin film microstrip structure with meandered signal line is properly constructed without any post processing steps. The overall filter occupies a compact circuit area of less than 0.25 λg × 0.25 λg and exhibits a 20 dB stopband fractional bandwidth of 21% and high-rejection of about-38 dB at centre frequency of 60 GHz. A good agreement between the predicted and measured results is observed up to 110 GHz.