In some applications network parameters vary over time in a manner that precludes the use of conventional swept frequency network analyzers. Swept measurements incur penalty both in terms of acquisition time, and in terms of registration between measurements taken at the beginning and at the end of a sweep. Disclosed is an architecture and method for real-time analysis of network parameters. Example applications are presented, ranging from thermal drift of amplifiers, to microwave imaging of moving objects, to characterizing materials on conveyors, to characterizing plasma buildup, and many more.