Spectrum analyser and phase noise tester combine

The R and S FSUP is billed as the first instrument specially designed for measuring phase noise and for characterising RF signal sources.

The R and S FSUP is billed as the first instrument specially designed for measuring phase noise and for characterising RF signal sources.

The instrument incorporates the company's many years of experience in developing high-quality spectrum analysers and low-noise oscillators and synthesisers.

It is the only instrument in the world that combines a spectrum analyser and a phase noise tester up to 8, 26.5 or 50GHz.

Users will profit from simpler and more flexible test sets at a considerably lower price.

To develop and produce high-quality transmit and receive equipment such as communications and broadcast systems or radar, users need the conventional measurements of both a phase noise tester and a spectrum analyser.

A typical task, for example, involves measuring the oscillator's phase noise, harmonics, settling or power in the adjacent channels while testing transmit and receive modules.

The R and S FSUP provides high convenience and the versatility required for this.

When measuring phase noise, the instrument compares the "signal source" DUT with a reference source.

The R and S FSUP can use external as well as internal references for this purpose.

In addition, the user can select the source for regulating the required 90-degree phase offset on the phase comparator.

If desired, the ideal settings for the measurement are selected automatically by the instrument.

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 640MHz and a frequency offset of 10kHz, the phase noise value of the R and S FSUP with an internal reference source is -136dBc (1Hz) and at 10MHz frequency offset -165dBc (1Hz).

The R and S FSUP-B60 option provides the signal source analyser with two parallel receive paths.

The symmetrical structure allows a cross-correlation between the two paths.

The R and S FSUP can thus eliminate the uncorrelated inherent noise of the internal reference sources.

This improves the dynamic range by up to 20dB, depending on the number of averages.

Furthermore, the R and S FSUP allows users to mark and list all interference lines or, alternatively, to suppress interference lines.

Integral parameters such as residual FM/PM or RMS jitter are also displayed.

The phase noise tester can record the level or the frequency of the signal source as a function of time and thus display settling and switching processes at high-frequency sources with high resolution.

Thus, the instrument is also able to precisely analyse the behaviour of signal sources in the time domain.

To measure phase noise or to record VCO tuning characteristics or how the level and frequency vary as a function of the supply voltage, extensive settings of the oscillator's supply and tuning voltage are necessary.

The R and S FSUP provides two independent, extremely low-noise DC supply outputs, a negative supply voltage and two tuning voltage sources for this purpose.

The high-end R and S FSU spectrum analyser integrated in the instrument rounds out the functionality of signal source analysis by allowing users to perform measurements on other parameters, such as harmonic suppression, spurious emissions or adjacent channel power, that are needed for the development and production of high-frequency modules and equipment.

The R and S FSUP can even measure the noise figure with the aid of a noise source and the optional R and S FS K30 noise measurement software.

The special advantage of the integrated spectrum analyser, however, is mainly that in comparison with other solutions it not only simplifies test sets and makes them more flexible but also reduces investment costs.

This is why Rohde and Schwarz designed this unique concept for the market segment of phase noise measurements.

"For developing high-quality oscillators or synthesisers, users always need a spectrum analyser in addition to the phase noise tester in order to fully test their circuits", explains Josef Wolf, Director of the Subdivision for Spectrum and Network Analysers.

"With the spectrum analyser already integrated in the R and S FSUP, it is no longer necessary to purchase such an instrument".

"And this also reduces the space required in a test rack in production, for example".

Rohde and Schwarz has long-standing experience in spectrum analysis.

"We've been pushing limits in this field for 20 years and continue to pave the way for innovative solutions", Wolf says.

"It was thus obvious for us to extend this know-how to the field of phase noise analysis".

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