Multiband Microstrip Rectenna Using ZnO-Based Planar Schottky Diode for RF Energy Harvesting Applications

Area of Science:

• Electrical Engineering
• Electromagnetics
• Wireless Power Transfer

Background:

• Radio frequency energy harvesting is crucial for powering low-power electronic devices.
• Existing rectenna designs often face limitations in bandwidth and efficiency.
• The need for compact, high-performance rectennas for dedicated applications is growing.

Purpose of the Study:

• To design and demonstrate a single-substrate microstrip rectenna for dedicated radio frequency energy harvesting.
• To enhance antenna impedance bandwidth using specific geometric modifications.
• To integrate a high-performance rectifier circuit for efficient energy conversion.

Main Methods:

• A microstrip antenna with a moon-shaped cut and a U-shaped slot in the ground plane was designed for ultra-wide bandwidth (UWB).
• A shunt half-wave rectifier (SHWR) circuit incorporating a planar Ag/ZnO Schottky diode was implemented.
• The rectenna's performance was simulated and experimentally validated.

Main Results:

• The UWB antenna achieved a bandwidth from 3 GHz to 25 GHz (-6 dB reflection coefficient).
• The rectenna system demonstrated a maximum measured output DC voltage of 600 mV.
• A peak measured efficiency of 25% was achieved at 3.5 GHz with 0 dBm input power.

Conclusions:

• The proposed single-substrate microstrip rectenna effectively harvests RF energy over a broad frequency range.
• The geometric modifications significantly improved the antenna's impedance bandwidth.
• The integrated rectenna system shows promising performance for dedicated energy harvesting applications.