Aeroflex has added a new test capability to its PN9500 phase noise test system. The digital spectrum monitoring (DSM) option PN95-DSM adds spectrum analyzer features to its low noise PN9500 phase noise and jitter testing system. The addition of digital spectrum monitoring simplifies and lowers the cost of RF and microwave testing by eliminating the need to purchase a separate spectrum analyzer for spectral purity applications. The PN9500 with DSM performs a much wider range of high-frequency measurements within one modular system. The DSM option allows the user to view the spectrum of a signal in the same way as a spectrum analyzer. The user can perform narrowband spectrum analysis, but can also opt to measure any wideband spectrum from DC to 18 GHz. The PN95-DSM measures power level, power variation, ACPR (adjacent channel power), and harmonic distortion. More measurements are possible by setting markers.