Agilent 5991-2059EN Using RF Recording Techniques to Resolve Interference Problems - Application Note c20140 free download

File name 5991-2059EN Using RF Recording Techniques to Resolve Interference Problems - Application Note c20140

Keysight Technologies Using RF Recording Techniques to Resolve Interference Problems Application Note Introduction System engineers characterizing interference in either commercial wireless or Electronic Warfare (EW) applications today face a difficult task. Interference, defined as anything that is not the signal expected, is a highly pervasive problem; one that can be quite difficult to address since its measure- ment can be unpredictable. Despite the challenge, the task of finding, identifying and analyzing inter- fering signals, intentional or not, in a crowded spectrum has become increasingly important in a wide array of applications. This application note introduces a method for using gapless recording to resolve RF interference problems in complex RF environments. The method uses the Keysight Technologies dual-channel M9392A PXI Vector Signal Analyzer with either a regular PC hard disk drive or external mass stor- age. When recording at wide bandwidths for long durations a RAID storage system is required. Data interface cards and modules are also used, as are Keysight's M9392A with the 89600 Vector Signal Analyzer (VSA) software. With gapless recording, engineers can now measure data continuously over long durations and ensure the capture of all RF events of interest when they occur. Measurement Generally speaking, there are two primary goals of RF interference testing: to ensure interoperability and compatibility. Interoperability testing focuses on de- Challenges sign compliance to a published standard, as well as margin testing, which helps engineers understand how well a system meets design criteria in the presence of real-world signal levels and interference. Compatibility testing, on the other hand, focuses on the "unintended interactions" between a system-under-test and other RF systems. It's important for engineers to understand whether radi- os from different vendors can interoperate with one another, as well as if all the systems in an RF environment can play together nicely. Ascertaining a system's susceptibility to impact from and on other RF assets may also be critical. Regardless of the RF interference testing in question, a number of critical measurement challenges exist. First and foremost, measuring RF target signals like intentional or unintentional interference in complex RF environments can be unpredictable. Additionally, intermittent failure modes make data capture par-