Network Analysis with a Single Sideband Generator of a High Image Suppression

A multistage single sideband generator is described consisting of a cascade of binary periodically switched phase shifters, e.g. with the values 180°, 90° and 45° for a double stage unit. With a special order of phase shift values any degree of suppression of the image sideband may be obtained even with imperfect phase shifters by increasing the number of stages. Therefore, in principle, any degree of accuracy in the homodyne measurement of amplitude and phase values of a device under test can be obtained using the described concept. The phase and amplitude information is retrieved from a bandpass filtered low frequency signal at the mixer output.