Modulated RF signal measurement setup

Digital radio-relay systems are particularly affected by the frequency selective nature of multipath fading. To know the effects of propagation on radio-relay systems, an experimental measurement setup was realized to characterize their susceptibility to multipath distortion. The measurement equipment is basically a recorder of the power density spectrum of the true received digital signal. It measures directly the RF power density spectrum; and only when the measured spectrum is substantially different from the reference spectrum, the power density spectrum is recorded. The entire operation is under the control of a computer.