Practical Considerations for the Use of Comb Generators in Shielding Effectiveness Measurements

A comparison of commercial-of-the-shelf (COTS) reference radiators for in-situ shielding effectiveness (SE) measurements is presented in this study. Pitfalls in current SE standards are examined, and improvements based on including small-footprint and self-reliant transmitting reference radiators is presented. The deployment of reference radiators based on comb generators is shown to simplify the SE measurement procedure, especially in the case of in-situ measurements. However, their performance is not expected to be the same as in the case of conventional techniques utilizing a signal generator with a power amplifier. On the other hand, in-situ measurements are known to be bound to higher measurement uncertainties, therefore the imperfections of the source are not as critical as in laboratory conditions. Still, in the case of SE measurements, the dynamic range (DR) is always of high importance. In this paper, parameters affecting the DR including output power level and pulse repetition frequency (PRF) are addressed both experimentally and theoretically. A comparison between the typical output power data of common reference radiators is shown, discussed, and experimentally validated.