High Directivity Reference RF Source and its Radiated Emission Model for Site Correlation

This article presents a configurable high directivity radio frequency reference noise source and its radiated emission (RE) simulation model. This noise source is a representative of actual programmable logic controller (PLC) and input output (IO) products with a high-speed gigabit backplane. It is designed to produce a reference noise signature from 30 MHz to 6 GHz with RE levels close to the class A electromagnetic radiation disturbance limits of CISPR 11 and CISPR 22. An RE model f this noise source was established to investigate the design factors. Multiple emissions’ scans were performed in two separate semianechoic chambers located in different facilities in order to test the repeatability of this noise source. The measurement results indicated that the noise source has very good repeatability and that it can serve as a reference noise source. The results were also used to evaluate the maturity of the simulation technology as well as to quantify the difference between chambers.