Wire-Bond Free Technique for Right-Angle Coplanar Waveguide Bend Structures

This paper presents a new wire-bond free technique for suppressing slot-line mode excitation in coplanar waveguides (CPWs) bends. The suppression of slot-line mode is obtained by applying a slow wave structure to the shorter slot of the right-angle bend. The structure is modified into a circular-shaped bend where the slow wave compensation is then used to equalize the electrical length of the inner and outer slots. The insertion loss of the modified CPW bend with slow wave structure is evaluated on a silicon substrate and is similar to straight CPW lines with return loss (
S

₁₁
) values below -20 dB over a 50-GHz bandwidth.