Measuring phase noise using a VNA with direct digital synthesizer sources
Testing frequency converters for 5G and satellite applications requires capturing several different parameters, including gain, phase, delay, intermodulation distortion (IMD), gain compression, and noise figure. Phase noise is challenging to measure as it is dependent on factors like internal architecture, type of oscillator, internal and external frequency references, and the effects of built-in capabilities. The source of the output phase noise also must be detected.
To measure phase noise, use a vector network analyzer (VNA) with direct digital synthesizer (DDS) sources to determine if the phase noise at the device's output is from the device itself or from the input signal. Add a third source to the test setup to use as a local source for the device under test (DUT) to make two-tone or two-stage frequency converter measurements without needing an external signal generator. The third source can also act as the reference signal for a DUT that requires an external reference clock signal or as the reference signal of another measurement instrument.
PNA-X phase noise measurement solution
Characterizing phase noise requires the capture of many key parameters like gain and noise figure. With direct digital synthesis (DDS) as signal sources, the Keysight PNA-X phase noise measurement solution makes phase noise measurements more stable while delivering improved measurement performance. Based on the Keysight PNA-X microwave network analyzer, the solution can measure active devices such as amplifiers, mixers, and frequency converters.