In this article, a novel six-port modulator is proposed and experimentally verified. The six-port modulator circuit is realized by using power dividers/combiners and polyphase networks for the first time. A prototype operating in 2.4-GHz instruments, scientifice and measurement (ISM) hand has been fabricated and experimentally verified, to show its performance as vector modulator. (C) 2011 Wiley Periodicals, Inc. Microwave Opt Technol Lett 53:2321-2324, 2011; View this article online at wileyonlinelibrary.com. DOI 10.1002/mop.26288