A wideband CPW-to-microstrip transition for millimeter-wave packaging

A broadband single layer vertical transition from CPW to microstrip has been developed for multilayer millimeter-wave circuits. The transition has exceptionally wide bandwidth and presents low insertion and return losses. A transition has been fabricated on a 100 /spl mu/m silicon wafer that shows approximately 0.3 dB of insertion loss and better than 10 dB return loss over 75-110 GHz. This transition can be used for the vertical integration of multi-layer millimeter wave circuits and packaging.