A Wideband Rectifier Design for Internet of Things (IoT) and Wireless Sensor Network Applications

This paper presents a compact wideband rectifier for low-power Internet of Things (IoT) and Wireless Sensor Network (WSN) applications, which enables efficient energy harvesting across multiple frequency bands. The proposed wideband rectifier operates efficiently over a broad bandwidth from 0.5-1.4 GHz covering the DTV band, LTE-700, ISM-900, and GSM-900. It employs a Coupled Three-Line Transformer (CTLT) as an impedance matching network to achieve a compact design and robust performance across a wide bandwidth. The circuit uses a voltage doubler configuration with SMS7630 diodes. It was designed, simulated, and validated through fabrication. At 0 dBm, it achieves a Power Conversion Efficiency (PCE) greater than 57% with a 3 kΩ load. The results show that the CTLT matching network can also maintain a high PCE over a wide range of load impedance from 2 to 7 kΩ. The design has a maximum efficiency of 74.2% at 0.65 GHz; it is compact with an electrical size of 0.428λ × 0.037λ, outperforming conventional rectifiers in efficiency and size. This rectifier is well-suited for powering battery-less IoT applications and WSN devices. Keywords: Coupled three-line transformer (CTLT), impedance matching network, power conversion efficiency (PCE), radio frequency energy harvesting (RFEH), rectifier, voltage doubler