Simplifying Pulsed Phase Noise Measurements

In pulsed radar systems, the phase noise of the receiver local oscillator sets the minimum signal level that must be returned from a target in order to be detectable. Since the overall dynamic range of the radar system is influenced by the noise of the transmitted signal, it is not only important to know the absolute noise of the individual oscillators but to know the residual or additive noise of the signal processing devices like power amplifiers and pulse modulators. Because the final signal in most radar systems is pulsed, making absolute phase noise measurements on the pulsed carrier is essential to determining the overall performance of the system.

This application note discusses the various trade-offs in a phase noise measurement of a pulsed RF signal generator and how easy it can be performed using the 7000 series signal source analyzer from Berkeley Nucleonics.