Impact of Leakage Current on Data Retention of RF-powered Devices During Amplitude-Modulation-based Communication

Devices powered by an electromagnetic field are inherently power-constrained and thus must carefully manage static and dynamic power. High ambient temperatures and field strengths can increase the temperature of RF-powered devices up to more than 100 degrees Celsius, thereby allowing the leakage current to rise to a dominating portion of the static power consumption. Leakage reduction techniques for application in RF-powered devices are examined in this paper with the goal to avoid malfunction of the device during amplitude modulation-based communication. Results show that without leakage reduction a correct operation cannot be guaranteed for the investigated 130 nm process technology for energy gaps that are defined by the widely applied ISO/IEC 14443-2 standard (100% field modulation). The evaluation of leakage reduction techniques shows that applying body biasing prolongs the data retention time by nearly 200%, while source biasing in general aggravated the circuit´s robustness against power gaps (reduction in data retention time by up to 76% loss), as did also voltage scaling (up to 98% reduction).