A new compact 3D SiGe 90° hybrid coupler using the meandering TFMS and shielded strip line at 20 GHz

This paper proposes a new scheme for realizing a compact 3-D 90° hybrid coupler based on the compact meandered thin-film microstrip (TFMS) transmission line and shielded stripline, and successfully demonstrates it by using the multi-layer 0.35 μm SiGe HBT Jazz process. The proposed coupler takes advantage of the multi-level metallization processes offered in SiGe technology. The intrinsic area of the fabricated 3D hybrid coupler is significantly reduced and has shown a size reduction of 95% in circuit area at 20 GHz compared to that of a conventional hybrid coupler using the TFMS configuration. Experimental results are presented in support of the novel 3D compact coupler.