Microwave Journal

Automating Radiated Immunity Testing

February 9, 2009

Systems designed to test for RF susceptibility or immunity contain a number of interconnected RF devices. By necessity, the majority of these test systems are configured as dynamic hardware solutions that address more than one of the ever changing EMC standards. Even manufacturers that have the luxury of only having to test to one EMC standard have discovered that mandated test levels and frequencies tend to increase over time, which impacts the selection of system rf devices. Considering the complexity of the newer EMC standards coupled with the complexity of the Equipment Under Test (EUT), the mechanics of simply “running” a standard test can be daunting. While theoretically one can conduct the required immunity tests manually, the amount of time and effort involved are so staggering, manual operation is only feasible when initially configuring a test system, when trouble shooting a system malfunction, or when very unique tests are required. The only viable option to this testing dilemma is automating the test by using a software driven RF test system controller that provides signal routing switch matrices. While productivity is increased markedly as the result of a significant decrease in the time required to perform EMC tests, a major side benefit of automation is repeatability. Aside from providing more accurate test results in a fraction of the time required to operate manually, repeatability is the single most significant characteristic of an automated system.

AR RF/Microwave Instrumentation has developed the SC1000 series of RF test system controllers to address the need for flexible automated systems. The SC1000 can accommodate up to three signal generators, four power amplifiers, four directional couplers, four unique RF loads for broadband RF testing from DC to 40 GHz and either a spectrum analyzer or receiver for EMI emissions testing. The SC1000 responds to remote commands via IEEE-488 (GPIB) or RS-232 as well as manual input via the front panel. Four open collector outputs (current sinking w/ an available +24VDC/500mA) and a switchable +12VDC source are supplied for those applications not supported by the existing SC1000 hardware. A four line vacuum fluorescent display provides operational information useful during initial system setup as well as when operating manually and system interlock capability is provided. This application note details the various uses and configurations of the SC1000 series.