Microwave Foreign Object Detection in a Lossy Medium Using a Planar Array Antenna

Area of Science:

• Electromagnetics
• Antenna Theory
• Sensor Technology

Background:

• Non-contact detection of foreign objects in lossy dielectric media (soil, vegetation, ice) is challenging.
• Applications include environmental monitoring and agricultural safety, requiring precise localization.
• Existing methods face limitations in accuracy and applicability to lossy environments.

Purpose of the Study:

• To design and experimentally validate an array antenna system for accurate foreign object localization in lossy media.
• To develop a non-contact detection scheme utilizing focused electromagnetic energy.
• To demonstrate the feasibility of precise positioning for embedded foreign objects.

Main Methods:

• Utilizing an array antenna system with optimized excitation distribution for focused electromagnetic energy.
• Measuring scattering parameters between transmitting and receiving antenna elements.
• Employing the method of maximum power transmission efficiency based on differential scattering parameter matrices.
• Fabricating and testing a 5x5 microstrip patch array antenna in colza oil with a copper block as the foreign object.

Main Results:

• Demonstrated effective focusing of radiated electromagnetic fields at the foreign object's location.
• Achieved accurate localization of a copper block immersed in colza oil.
• Validated the non-contact detection scheme's feasibility and precision in a lossy medium.

Conclusions:

• The proposed array antenna system enables precise non-contact foreign object detection in lossy dielectric media.
• The electromagnetic focusing technique proves effective for localization applications.
• This approach offers a promising solution for environmental monitoring and agricultural safety.