1–50-MHz VHF electromagnetic sensor-interface power-attenuation detector circuit

• Published in: International journal of electronics and communications 2012-06, Vol.66 (6), p.502-508
• Main Authors: Lazaro, Orlando, Rincón-Mora, Gabriel A., Vogt, Justin P.
• Format: Article
• Language: English
• Subjects: Electromagnetic interference; EMI; Peak detection; Power detection; Power sensor; Sensor
• ISSN: 1434-8411; 1618-0399
• DOI: 10.1016/j.aeue.2011.11.002

The natural but unwelcome byproduct of modern telecommunication systems is electromagnetic interference (EMI). These communication networks are dynamic and produce unpredictable position- and time-varying electromagnetic fields that interfere with sensitive high-performance electronics, for which shielding is often a necessity. The shield's ability to suppress electromagnetic noise, however, may change not only over time but also across environmental conditions. EMI sensors, as a result, play a critical role because arbitrarily over-sizing a shield to accommodate worst-case conditions is not an option in many portable and mobile applications. This paper presents a logarithmically compressed peak-detection EMI sensor-interface circuit that combines the complementary functional strengths of state-of-the-art power detectors to monitor and sense 1–50MHz of EMI with 5-bit accuracy across 16dB of dynamic range and under −40 to 40°C. The proposed circuit and printed-circuit-board (PCB) embodiment compensate for temperature variations as well as diode-induced errors to maintain and improve accuracy across a wide operating range.