The application of suppressed carrier double sideband signals to group delay measurements

A technique is described in which a suppressed carrier d.s.b. test signal is used to measure the variation in group delay within the baseband of a microwave video channel. The method is shown to be capable of avoiding errors caused both by differential sideband attenuation and by unwanted modulation components. A resolution of 5 ns has been achieved in the frequency range 0.5 to 10 MHz.