SDR-Based Shielding Effectiveness Measurement Technique Using Signals-of-Opportunity

Shielding effectiveness (SE) measurements of shielded cabinets can pose significant challenges because the typical procedure usually involves removing electronic equipment from the cabinet and relocating it to an accredited laboratory for measurements, a process known to be costly and time consuming. This paper proposes a novel measurement technique that utilizes signals of opportunity and software-defined radio (SDR) receivers to quickly estimate SE in a cost- and time-efficient manner. Moreover, this method facilitates continuous monitoring of the shielded environment to detect electromagnetic leakage resulting from intended or unintended shielding deterioration. Utilizing small antennas and affordable SDR-based receivers, the method enables on-site and continuous measurement of SE, even within cabinets heavily filled with electronics. This technique is particularly useful for TEMPEST cabinets because they are filled with electronics and require continuous monitoring due to the sensitivity of what is protected. Furthermore, its applicability may be extended to various other structures, where maintaining shielding integrity is critical. The paper concludes with a comprehensive discussion of the advantages and disadvantages of this measurement method.