Development of Compact and High-Efficient Simple CPW Rectenna for RF Energy Harvesting

The Wireless Body Sensor Network (WBSN) is used for communication of the sensor nodes operating on or inside the human body in order to monitor the human activities. Wearable sensors can monitor and record real-time information about one’s physiological condition and motion activities. Wearable sensor-based health monitoring systems may comprise different types of flexible sensors that can be integrated into textile fiber, clothes, and elastic bands or directly attached to the human body. In this context, wearable technology has been addressed to make humans (his clothes) able to communicate with, and be part of the interconnected network. The proposed rectenna architecture is designed to harvest energy efficiently in the vicinity of low intercepted power around 0dBm. The rectifier is composed of voltage doubler circuit with LC matching circuit. The antenna is commercially available from flexible conductive film, COCOMI®, Toyobo Co., Ltd. The overall rectifier dimensions are very compact 19.5 × 9.7mm2. There are a good agreement between the simulation and measurement results. For instance, the peak measured efficiency is 52% at −5dBm RF input power and the corresponding simulated value is 61%. The 63% peak measured efficiency is achieved at 5dBm with a terminal load 5kΩ