High-quality VNA accessories from Rohde & Schwarz

Even if a VNA is of high quality, the connection to the DUT can be hampered by network analyzer test cables and connectors that compromise this quality. Rohde & Schwarz wants to ensure that the singal from its VNAs reaches the DUT without a loss of integrity or voltage. This is why we offer cables featuring rugged construction as well as excellent phase and amplitude stability. Both series, R&S®ZV-Z9x and R&S®ZV-Z19x stand for excellent RF quality: The focus of the R&S®ZV-Z9x cables lies in mechanical crush resistance of the cable body, stability of the connections, and very low spring back and positioning resistance. The R&S®ZV-Z19x cable series stand for a smart body combined with high-performing standard connectors.

Electronic (automatic) calibration units apply automatically the following incorporated standards: open, short, match, (unknown) through. No manual connection of calibration standards is required. Thus, the automatic units are the most convenient and fastest way of calibration, and minimize operation errors such as mixing up standards during calibration, or poor connection reproducibility. Moreover, a number of test ports exceeding the number of cal-unit ports can be calibrated by repeated connection (eg. a two-port unit can calibrate a 4-port VNA, or even a 24-port mid-range R&S®ZNBT). On the other hand, the application is limited to the connector types and gender (except user supported re-characterization), and single standards are not available.

Manual calibration kits are more flexible: with a single high-end kit, or two economy kits (male & female seperate), all male/female combinations are supported. Standards are available for one-path-two-port calibration, and completion with lines for TRL and other special calibration techniques is possible. Moreover, the standards can be used as auxiliary components, e.g. to terminate a test port or to have a through connection available.

Even after a carefully carried out system error correction, the verification of the resulting accuracy is an important and justified aspect: e.g. aging of the calibration kit, limited reproducibility of the connections, and the actual test parameters may cause an uncertainty under real conditions, which is different from the typically idealized data sheet specificatons. However, as simple re-connection of the beforehand used calibration standards is misleading and just reveals the reproducibility of the calibration step - even severe calibration errors may remain hidden. A reliable uncertainty verification requires the additional measurement of known devices, with S-parameters different from the those of the calibration standards: This is enabled by the components included in the R&S®ZV-Z4xx verification kits. At the final stage, the verification procedure is supported by option R&S®ZNA-K50(P), presenting the measurement traces with the actual error bars.

A VNA system error correction consists of connecting the calibration devices (manual kit standards or calibration unit) each time for calibration, and to disconnect them when the calibration step is completed. But there are application cases where no access to the reference plane is given, the most important ones are thermal vaccum chambers (TVAC): typically a calibration update is required after cooling down and evacuation. The solutions are InLine CalUnits, as they remain permanently connected in the reference plane, and a re-calibration can be initiated remote controlled on a key stroke.