Microwave 3D Imaging System Featuring the Phase Coherence Factor for Improved Beamforming

Area of Science:

• Biomedical Engineering
• Medical Imaging
• Electromagnetics

Background:

• Radar-based imaging offers a non-ionizing alternative for breast cancer detection.
• Ultrawideband (UWB) antennae provide high resolution for imaging applications.
• Conventional beamforming algorithms struggle with noise and interference in complex media.

Purpose of the Study:

• To develop and validate an improved radar imaging system for enhanced breast cancer detection.
• To incorporate a phase coherence factor (PCF) into the delay and sum (DAS) beamforming algorithm.
• To suppress noise and improve the signal-to-clutter ratio in radar breast imaging.

Main Methods:

• A 32-element ultrawideband antenna array (p-slot) was utilized in a hemispherical breast radome.
• A novel reconstruction algorithm combined phase coherence factor (PCF) with delay and sum (DAS) beamforming.
• The system was tested using 3D breast models with varying tissue compositions and simulated tumors.

Main Results:

• The PCF-weighted DAS algorithm accurately detected 5 mm tumors in dense breast models.
• Achieved an average signal-to-clutter ratio of 7.0 dB and a full-width half-maximum of 2.3 mm.
• Demonstrated superior performance compared to other beamforming techniques, even at low contrast ratios (1:2).

Conclusions:

• The proposed PCF-weighted DAS algorithm represents a significant advancement in radar breast imaging.
• This improved system shows high potential for accurate and sensitive tumor detection.
• The findings support progression towards clinical trials for human subjects.