A140 Rohde & Schwarz Local Control Unit for ZV Series Vector Network Analyzer

The Rohde & Schwarz ZVM/ZVK Vector Network Analyzers are compact instruments with integrated generator, two reference and two receiver channels and a bidirectional test set. This can be extended by attenuators with integrated switches in the generator and receiver paths. With this configuration, ZVM and ZVK offer direct access to all reference and receiver channels. This concept makes ZVM and ZVK well equipped for complex test setups, for example for bidirectional measurements on power amplifiers.

The ZVM and ZVK have two independent synthesizers for the generator and the receiver. In the receiver sections, fundamental mixing is used up to high frequencies to provide the excellent dynamic range and outstanding selectivity, enabling straightforward measurements on frequency-converting DUTs or DUTs with extremely high selectivity.

The ZVM and ZVK feature modern calibration techniques patented by Rohde & Schwarz that allow full two-port calibration using fewer or only partially known standards. This simplifies the design of calibration standards used for example in test fixtures or on wafers. Thus calibration in non-coaxial systems can be performed with a minimum of effort at maximum accuracy and dynamic range.

The Virtual Embedding Networks option enables virtual embedding of arbitrary linear two-port networks into the test setup. The required data are obtained from a measurement of the existing network or generated by CAE tools from the theoretical model.

In tests of components that have to be matched to a given impedance, the matching network can thus be taken into account through mathematical algorithms of ZVM and ZVK instead of using the physical network. This method guarantees high accuracy, ideal reproducibility and maximum reliability without any loss of speed - great advantages especially in production.

Conversely, by de-embedding, the influence of a known network can be eliminated. The S-parameters of a chip can be analyzed, compensating for the effects of its housing and bonding leads through de-embedding.

By transforming measurement data from the frequency to the time domain, discontinuities or impedances along the DUT can be displayed as a function of DUT length. With a maximum number of 2001 points, ZVM and ZVK can measure even very long DUTs with high resolution. Five filters allow the location of a discontinuity and the sidelobe suppression to be determined with optimum resolution. The S-parameters of a given discontinuity can be displayed in the time domain by setting a window (gating). An additional processor module included in the corresponding option accelerates data processing and the display of results to provide even realtime display - a valuable aid, for example in the tuning of bandpass filters with time domain transformation.

ZVM and ZVK are based on Windows NT. The user has complete access to the hard disk, the floppy disk drive and all interfaces of the internal PC. This allows, for example, the connection of an external monitor, the installation of any type of printer, or the use of software tools on ZVM or ZVK for result processing or control of the network analyzers via the IEC/ IEEE bus or an internal RSIB*) data bus. ZVM and ZVK can thus act as controllers of their own or for a complete test or production system. Moreover, the internal PC enables control and data exchange via Ethernet.

In the decoupled mode, the frequency grid, measurement bandwidth, calibration technique and measurement mode can be configured independently for each of the four display channels. In amplifier measurements, this allows the simultaneous measurement and display of important parameters in quasi-realtime, such as gain, compression point (power sweep) and harmonics versus power or frequency, or compression point versus frequency.

The Rohde&Schwarz two-port calibration techniques reduce the number of required calibration standards to a minimum of 2. This significantly cuts the time required for manual calibration. The short measurement time of <500 µs or <700 µs per point guarantees minimum sweep times through to realtime display. The output of a marker value via the IEC/IEEE bus takes less than 5 ms, the transfer of a complete trace (200 points) less than 15 ms. These features are the basis for the excellent performance of ZVM and ZVK both in manual operation and in automated test systems.