High-performance flip-chip technique with an optimized coplanar waveguide

A new design technique for flip-chip structures with an optimized coplanar waveguide (CPW) is proposed. One of the features of this technique is that nide-gap CPW patterns are formed to reduce the excessive capacitance betwee n the two signal lines in the flip-chip structure. Thus, it is possible to achieve a return loss in excess of 28 dB up to 58 GHz. Another feature is t hat the design method is improved by using two-dimensional (2D) cross-secti onal analysis to optimize the parameters of the flip-chip structure. The de sign turn-around time is at least one-third that of the method using only t hree-dimensional (3D) electromagnetic field analysis. By applying our metho d to the design of a wide-band photoreceiver, we estimated a 3-dB down band width up to 60 GHz. These results show that our proposed techniques are use ful for millimeter-wave or wide-band communication systems. (C) 2000 John W iley & Sons, Inc.