System Overview
R&S
®
ZVT
89
Getting Started 1300.0045.62 ─ 10
As an alternative to true differential mode, the Defined Coherence Mode provides sev-
eral source signals with defined phase and amplitude relation.
3.5.6 Measurements on Pulsed Signals (R&S ZVA-K7)
Measurements on pulsed RF signals are required in many areas of RF and microwave
technology. Pulsed signals are used in mobile phone applications and radar systems,
and amplifiers are typically designed for pulsed rather than continuous wave (CW) con-
ditions.
The analyzer performs pulsed measurements in analogy to a time sweep (i.e. at con-
stant receiver frequency), but with a much higher sampling rate of 12.5/ns. The raw I/Q
amplitudes are written into a ring buffer and processed at the end of each sweep. The
buffer size allows for a maximum recording time (sweep time) of 3 ms. Due to the high
sampling rate and the large IF bandwidths available, it is possible to obtain profiles for
pulse widths from approx. 200 ns to the maximum recording time. Of course it is also
possible to measure a sequence of pulses up to the maximum recording time.
3.5.7 Converter Control (R&S ZVA-K8)
Measurements at frequencies beyond the analyzer's operating range (mm-wave mea-
surements) are achieved by combining a frequency-converting measurement with an
external test set (frequency converter). The frequency converters use frequency multi-
pliers to transform the RF source signal from one of the network analyzer ports into a
high-frequency stimulus signal. A dual directional coupler separates the reference and
measurement channels from the waveguide test port. A second signal (Local Oscilla-
tor, LO) is used for down-conversion of the reference and measurement channels. The
LO signal can be provided either by a second analyzer port or by an external genera-
tor. The down-converted signals are fed to the REF IN and MEAS IN input connectors
of the analyzer port providing the RF source signal.
Option R&S ZVA-K8 also comprises option ZVA-K4, Frequency Conversion.
3.5.8 Mixer Delay w/o LO Access (R&S ZVA-K9)
Measurement of a mixer's absolute or relative group delay. The mixer delay measure-
ment is an extension of the scalar mixer measurement: The network analyzer gener-
ates a two-tone RF signal as a mixer input signal and measures the converted IF sig-
nal at the mixer output. The mixer delay is derived from the relative phases of the two-
tone signals at the mixer input and the mixer output.
Compared to conventional measurement methods, the mixer delay measurement
offers several additional advantages.
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No external mixers are needed.
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A network analyzer with standard functionality is sufficient.
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Easy calibration using a calibration mixer.
Optional R&S ZVT Extensions
