SiGe BiCMOS balanced transmission line based on coplanar waveguide and split ring resonator

Abstract

AbstractIn this work, the design of a right‐/left‐handed composite transmission line implementation with passband characteristics is demonstrated on 0.13 µm silicon‐germanium bipolar CMOS (SiGe BiCMOS) technology. The proposed structure is formed by a shorted coplanar waveguide transmission line loaded with split ring resonators (SRRs). As it will be shown, by controlling the geometry of the SRRs as well as their electric coupling with the host line, it is possible to achieve a balanced passband response with widespread bandwidth at millimeter wave frequencies. Besides, this paper introduces a configuration that allows to significantly lower the resonant frequency of the SRRs by loading the rings with Metal‐Insulator‐Metal capacitors. It will be illustrated how this approach allows to reduce the center band frequency of about 40% preserving the balanced behavior and without increasing the resonator size. Finally, the proposed design was experimentally validated with a prototype exhibiting an extended passband with a fractional bandwidth of 19.3% and −3.2 dB of insertion loss around the central frequency of 60 GHz. The use of these transmission lines can be foreseeing in high‐capacity millimeter wave communication systems which require compact passband blocks integrated on chip.