A new type of SiGe 3D coplanar strip and its application to the design of low loss ECPW and TFMS series/shunt stubs

On-chip transmission lines in silicon technologies suffer from the low-resistivity substrate and geometric limitations imposed by layout and metal density design rules. In this paper, we demonstrate that 3D coplanar strip (3DCPS) transmission lines can be utilized to overcome both problems by taking advantage of the multiple metal layers available. A test chip was designed to validate the concept. The paper also presents a family of novel 3D series/shunt matching stub structures based on the 3DCPS and ECPW/TFMS combination. Experimental results are presented in support of the proposed structures.