This paper presents a fully integrated CMOS front end for Radio frequency energy harvesting as a practical solution to power implanted medical devices within the human body. The system incorporates an on-chip tunable impedance matching network and a cross-coupled differential drive (CCDD) rectifier featuring a body biasing technique to enhance input sensitivity. The rectifiers are interconnected in a cross-coupled configuration, leading to reduced ON resistance and minimal reverse leakage current during forward and reverse-biased states, respectively. Also the rectifier output is regulated using Power on Reset, Bandgap Voltage Reference and Low Dropout Regulator blocks, which are designed to consume low power. These utilizing TSMC 0.18 μm CMOS technology, the RFEH front end is tailored for operation in the Wi-Fi 6 (5 GHz) and Wi-Fi 6E (6 GHz) frequency bands, achieving an enhanced sensitivity of -20 dBm at the 1.2-V output voltage. Overall this compact system finds potential applications in implantable medical devices.

This paper introduces an on-chip hybrid rectifier tailored for RF energy harvesting at 2.4 GHz. Leveraging advancements in CMOS technology, this solution offers a novel approach to powering devices, particularly suitable for implantable biomedical devices and applications. This proposed architecture features 3-stage reconfigurable hybrid rectifiers, with each stage comprising a regular threshold voltage ($V_{th}$) MOS rectifier for high input power and a low ($V_{th}$) MOS rectifier for low input power. The cross-coupled connection of both rectifiers ensures minimal ON-resistance and low reverse leakage current during forward and reverse biased conditions, respectively. Through effective reconfiguration of power paths, the proposed system achieves high power conversion efficiency across a broad input power range. This proposed system is designed and Implemented in UMC$0.18~\mu $m CMOS technology with a Wi-Fi frequency of (2.4 GHz), the measured results are demonstrating an efficiency exceeding >35% for input power levels ranging from −23 dBm to −12 dBm, driving a load of 40 K$\Omega $.

This paper presents a novel RF energy harvesting system designed to operate within the WiFi-6 frequency band. The system incorporates reconfigurable rectifier stages, offering flexibility and adaptability. Along with the rectifier stages, it includes a comparator, a ring counter, and a Low Dropout Oscillator (LDO). The system uses TSMC 180 nm technology at 2.4 GHz and maintains a steady output voltage of 2.3 V. In this design, the rectifier stages are precisely adjusted to ensure that the input voltage for the Low Dropout Oscillator hovers around 2.5 V, accounting for a 200 mV dropout voltage. This adjustment significantly enhances the efficiency of the Low Dropout Oscillator. Additionally, the rectifier’s conversion ratio is configured to compensate for any impedance mismatch caused by variations in the input power. The impedance of the rectifier is derived through a large signal SP analysis, allowing for the determination of appropriate impedance matching network values. As a result, the system achieves a sensitivity of -14 dBm while maintaining an output voltage of 2.3 V.