Several signal via geometries are analyzed for across and through transmission by varying the drill‐hole diameter, ratio of the pad and antipad diameters to drill‐hole diameter, and number of ground planes. Time‐ and frequency‐domain results showing impedance‐, insertion‐, and return‐loss trends, which are useful for designing via geometries for high‐speed transmission, are obtained. © 2005 Wiley Periodicals, Inc. Microwave Opt Technol Lett 48: 315–320, 2006; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.21336