Design and Implementation of a Virtual Instrument for Electromagnetic Field Strength Measurement

After simply analyzing the background in traditional electromagnetic environment test items, a computer-based data acquisition (DAQ) system coupled by means of a general purpose instrumentation bus (IEEE488/ GPIB) with a signal generator is used to create a virtual instrument system with electromagnetic filed strength measurement capability. The software signal-processing capability of the data acquisition system was used to compensate instrument measurement deficiencies and to enhance signal capture. And the virtual instrument is shown to provide auto-increment frequency signals as the test required. The virtual instrument software module is applied to develop the front panel and background calculation and controlling program. The system is programmed in modules, and can be transfer or extended to the other systems. The design theory and technology of this automatic measurement system can also be applied to the other electromagnetic compatibility (EMC) test items, to overcome the difficulties in manual operation, and enhance the test quality and efficiency.