Introduction

A coplanar waveguide (CPW) is a type of planar transmission line used in microwave integrated circuits (MICs) as well as in monolithic microwave integrated circuits (MMICs). The unique feature of this transmission line is that it is uniplanar in construction, which implies that all of the conductors are on the same side of the substrate. This attribute simplifies manufacturing and allows fast and inexpensive characterization using on-wafer techniques. This chapter gives an overview of the advantages, types, and typical applications of CPW.