The 70300A RF tracking generator adds stimulus-response measurements to a Keysight 70000 series spectrum analyzer, enabling accurate characterization of gain, frequency response, isolation, and return loss. The wide dynamic range (>124 dB with 70300A and 71100C) makes accurate measurements of filter rejection and switch isolation without the need for time-consuming averaging. The system has very high selectivity, with resolution bandwidths as narrow as 10 Hz. High selectivity allows measurements in the presence of other signals-a key advantage when measuring LO-to-RF isolation of a mixer or the return loss of an active antenna system. Unlike a point-by-point measurement system, the Keysight 70000 scalar system sweeps quickly and provides continuous data. The system is controlled using the 70871A scalar personality.