Coplanar wave-guide grounded lines (CPWG) have been designed for being realized by micromachining of high resistivity silicon wafers. Actually, different configurations have been compared between them by changing the dimensions of micromachined via-holes, as well as their number and separation, to get the optimal electrical matching conditions for CPWG lines. Wide-band matching and low losses have been predicted up to 30 GHz, and preliminary experimental results about the technology have been obtained.