Impact of Antenna Design on Image Quality in Breast Microwave Radar

Limited access to breast cancer screening contributes to late-stage diagnoses in low-income and remote communities. Breast microwave sensing (BMS) systems provide a promising, cost-effective, and portable alternative to traditional screening methods. However, existing BMS systems vary substantially in design, equipment configuration, measurement protocols, and image reconstruction techniques. This work compares three common antenna types used in BMS systems-horn, Vivaldi, and flexible Printed Circuit Board (PCB)-to investigate how antenna design influences image quality. We evaluated spatial resolution, signal-to-noise ratio (SNR), signal-to-clutter ratio (SCR), and image accuracy using a standardized radar reconstruction method. Results show that the Vivaldi antenna achieved the best spatial resolution and highest SNR and SCR among the three despite having a lower gain and larger beamwidth than the horn antenna. These findings suggest that other antenna factors, such as crosssectional area, radiation pattern, and housing design, play an important role in microwave imaging beyond simply antenna gain, return loss and bandwidth. Understanding how these design parameters affect image quality is crucial for developing robust and accurate BMS systems, particularly for deployment in lowincome and remote regions.