Concepts and Features
R&S
®
ZNA
186
User Manual 1178.6462.02 ─ 12
For a complete list of options, accessories, and extras refer to the product brochure or
to the "Options" section of the R&S
ZNA product pages on the Internet.
The following sections provide an introduction to the software and hardware options
described in this documentation. The use of external power meters, generators and
generic devices does not require any additional hardware or software options; it is
described at the end of the chapter.
5.7.1
Spectrum Analyzer Mode
Option R&S
ZNA-K1
Option R&S
ZNA-K1 enables spectrum analysis measurements on the R&S
ZNA.
5.7.2
Time Domain Analysis
Option R&S
ZNA-K2
The network analyzer measures and displays complex S-parameters and other quanti-
ties as a function of the frequency. The measurement results can be filtered and math-
ematically transformed to obtain the time domain representation, which often gives a
clearer insight into the characteristics of the DUT.
Time domain transforms can be calculated in band pass or low pass mode. For the lat-
ter, the analyzer offers the impulse and step response as two alternative transformation
types. A wide selection of windows can be used to optimize the time domain response
and suppress side lobes due to the finite sweep range. Moreover, it is possible to elimi-
nate unwanted responses using a time gate and transform the gated result back into
the frequency domain.
For a detailed discussion of the time domain transformation including many examples,
refer to the application note 1EZ44 which is available on the R&S internet at
www.rohde-schwarz.com/appnotes/1EZ44
.
5.7.2.1
Chirp z-Transformation
The Chirp z-transformation that the analyzer uses to compute the time domain
response is an extension of the (inverse) Fast Fourier Transform (FFT). Compared to
the FFT, the number of sweep points is arbitrary (not necessarily an integer power of
2), but the computation time is increased by approx. a factor of 2. This increased com-
putation time is usually negligible compared to the sweep times of the analyzer.
The following properties of the Chirp z-transformation are relevant for the analyzer set-
tings:
●
The frequency points must be equidistant.
●
The time domain response is repeated after a time interval which is equal to Δt = 1/
Δf, where Δf is the spacing between two consecutive sweep points in the frequency
domain. For a sweep span of 4 GHz and 201 equidistant sweep points, Δf = 4
Optional Extensions and Accessories
