Coplanar waveguides have been increasingly used as feeding lines
in the design of microstrip antennas, especially when used in the
millimeter-wave applications. The reasons are that they have low
radiation leakages and that they allow shunt and series connections
on the same side of the planar substrate and avoid the use of via
holes. In addition, the substrate can be made relatively thick such
that the microstrip antenna integrated on the same substrate can be
made well-matched with good efficiency and improved bandwidth.
Open-end coplanar waveguide fed microstrip antennas have been
studied experimentally [ 11, [2]