Agilent Techniques for Precise Measurement Calibrations in the Field - Application Note 5991-0421EN c2014072 free download

File name Techniques for Precise Measurement Calibrations in the Field - Application Note 5991-0421EN c2014072

Keysight Technologies Techniques for Precise Measurement Calibrations in the Field Using FieldFox Handheld Analyzers Application Note Abstract This application note, which applies to cable and antenna and vector network analysis, discusses recent advances in vector network analyzer calibration and compares measurements using different calibration types for a variety of RF and microwave devices including cables, filters and amplifiers. A FieldFox handheld analyzer is used to make the various measurements, as it can perform precise measurements and analysis in the field. Introduction Installation, troubleshooting and maintenance of RF and microwave systems and components require measurements of their reflection and transmission characteristics within a variety of indoor and outdoor environments and conditions. These measurements are typically made using a handheld vector network analyzer (VNA) having a user calibration that is preformed in the field. Measurement accuracy, calibration convenience, sweep speed and analyzer portability are extremely important requirements as testing often occurs under extreme conditions ranging from high elevations, such as outdoor tower and mast installations, to confined spaces, required in shipboard, aircraft and vehicle applications. The required measurements are easily obtained using a VNA with a simple user calibration and fast measurement sweep, which are available on FieldFox handheld analyzers. Measurement accuracy when using a VNA is directly related to the type of user calibration selected and the associated test configuration. The test configuration includes test cables and adapters required to interface the Device Under Test (DUT) to the VNA. The types of calibrations available on FieldFox range from the built-in calibration (CalReady), which is available immediately at instrument turn-on, to more complex user calibrations requiring measurements from a set of high-quality calibration standards. Selection of the calibration type (cal type) is often a trade-off between measurement accuracy, speed and the complexity of the calibration process. For example, Figure 1 shows a comparison of the measured insertion loss (S21) of a short coaxial cable using two different cal types available on FieldFox. The yellow trace is the cable measurement using an innovative cal type named QuickCal and the blue trace is the measurement of the same cable using a traditional Full 2-Port mechanical calibration. The Full 2-Port calibration process requires that the user make seven connections to various high-quality calibration standards while QuickCal was performed without the need for any calibration standards. As shown in the figure, there is very little difference between the two measurement results yet the