Rohde & Schwarz introduced the R&S FSUP, the company's first instrument designed exclusively for measuring phase noise and characterizing RF signal sources. The instrument incorporates the company's many years of experience in developing high quality spectrum analyzers and low noise oscillators and synthesizers. Rohde & Schwarz claims this to be the only instrument that combines a spectrum analyzer and a phase noise tester covering 8, 26.5 or 50 GHz.
When measuring phase noise, the instrument compares the signal from the device under test with a reference signal source using its internal reference or an external reference. The user can select the source for regulating the required 90-deg. phase offset on the phase comparator. Together with other measurement parameters such as bandwidth, filter type and number of averages, the offset frequency range is also easy to configure. At an input frequency of 640 MHz and a frequency offset of 10 kHz, the phase noise of the R&S FSUP with an internal reference source is < - 135 dBc/Hz and at < - 165 dBc/Hz with a 10 MHz offset.