Effects of ground equalization on the electrical performance of asymmetric CPW shunt stubs

A hybrid technique is used to study the effects of ground equalization on the electrical performance of CPW (coplanar waveguide) shunts stubs. Extensive experiments have been performed on CPW circuits with bond wires and air bridges. The circuits with bond wires are found to be much easier to fabricate, but some of the accuracy is sacrificed. Air bridges provide much more accuracy in the measurements, though they are more difficult to fabricate. It has been found that the asymmetric stub has a lower Q than the symmetric stub with the same dimensions. In addition, it has been demonstrated that a longitudinal air bridge is not needed in an asymmetric CPW shunt stub if the dimensions of the stub are very small. >