A novel broadband uni-planar MMIC ring coupler for wireless LANs applications

A novel uni-planar broadband millimeterwave MMIC ring coupler is reported. The MMIC coupler incorporates a coplanar waveguide (CPW) and an asymmetric coplanar stripline (APCS) as well as a phase inverter for compact and broadband design. On-wafer measurements show that the coupler has fairly good performance in terms of coupling amplitude and phase balance, return loss, and isolation. This coupler is suitable for an RF front-end integrated design for millimeter wave wireless LANs applications.