Homogeneous microwave near-field power focusing using a cylindrical antenna array

Area of Science:

• Electromagnetics
• Antenna Theory
• Wave Propagation

Background:

• Microwave near-field power focusing (NFPF) is crucial for applications like wireless power transfer.
• Existing methods often require extensive computational resources for optimization.
• Accurate analytical models are needed to improve efficiency and predictability.

Purpose of the Study:

• To develop and validate a novel analytical approach for NFPF using a cylindrical array of electric line sources.
• To introduce a quantitative metric, focus ability (FA), for assessing power focusing performance.
• To reduce the computational time required for optimizing excitation signals.

Main Methods:

• An analytical model for NFPF was developed for homogeneous linear media using a z-axis cylindrical array.
• The focus ability (FA) parameter was defined and optimized to guide excitation signal design.
• COMSOL and CST full-wave simulations were used for theoretical validation and comparison with dipole antenna arrays.

Main Results:

• The theoretical analysis and simulation results demonstrate the effectiveness of the proposed NFPF method.
• Optimized excitation signals derived from the analytical approach successfully enabled power focusing with dipole antenna arrays.
• The FA parameter effectively quantifies focusing capabilities across different media and antenna configurations.
• A significant reduction in optimization time was achieved compared to purely simulation-based methods.

Conclusions:

• The proposed analytical approach provides an efficient and accurate method for microwave near-field power focusing.
• The focus ability (FA) parameter is a valuable tool for designing and evaluating NFPF systems.
• The method offers a practical solution for reducing computational complexity in antenna array optimization for power focusing.