A 950-MHz Rectifier Circuit for Sensor Network Tags With 10-m Distance

TLDR

The study proposes a 950‑MHz wireless power transmission system with a high‑sensitivity rectifier to enable battery‑life‑free sensor tags. The system recharges a secondary battery on the tag via the base station’s RF output, using a 0.3‑µm CMOS rectifier with dynamic gate‑drain biasing. Measurements show the rectifier can recharge a 1.2‑V battery from –14 dBm RF input with 1.2 % efficiency, enabling 10‑m communication at 4 W base‑station output.

Abstract

This paper presents a 950-MHz wireless power transmission system and a high-sensitivity rectifier circuit for ubiquitous sensor network tags. The wireless power transmission offers a battery-life-free sensor tag by recharging the output power of a base station into a secondary battery implemented with the tag. For realizing the system, a high-sensitivity rectifier with dynamic gate-drain biasing has been developed in a 0.3-/spl mu/m CMOS process. The measurement results show that the proposed rectifier can recharge a 1.2-V secondary battery over -14-dBm input RF power at a power conversion efficiency of 1.2%. In the proposed wireless system, this sensitivity corresponds to 10-m distance communication at 4-W output power from a base station.