The paper contains a brief review of the various techniques employed for the sampling of RF and microwave signals, and reference is made to subharmonic sampling as one of the possible applications. Particular attention is given to the two- and four-diode gate arrangements and the associated pulse strategies for fast switching time are discussed, as are the theoretical and practical aspects associated with the use of finite risetime sampling pulse trains. The design and operation of an experimental 10 GHz GaAs FET unit are given in detail, and recommendations are given in the concluding Section as regards development effort in sampling gates.