Making phase noise measurements at frequencies above 7 GHz can be difficult enough even without running into phase noise test set limitations. Although many of the test set manufacturers are making their systems capable of measuring higher frequencies these days, the cost for these systems is extremely high and most of us prefer to find ways of using existing or onsite instrumentation for now. The input frequency limitation for many automated phase noise test sets is around 7 GHz, so how do you measure the phase noise performance of signals > 7 GHz? A common method is to mix the DUT at the higher frequency with another signal and mix down to a frequency that the phase noise test set can measure accurately. The data can then be normalized to determine the phase noise at the DUT frequency. Wenzel’s Golden Frequency Source for Mixing includes our lowest phase noise oscillator (GMXO-FR) which produces several high quality signals that can be used for mixing with the DUT signal. Also provided within the box is a mixer, which is convenient for mixing one of the Golden signals provided with the DUT. You just need to provide the appropriate filter and amplifier as needed to select the desired signal and level to be used for testing with your phase noise test set.