This letter presents the design, fabrication, and characterization of an ultra-wideband (UWB) microstrip patch antenna engineered for the early detection of breast tumors. The proposed design offers a nearly constant radiation pattern, high gain, and compact size through the utilization of an artificial magnetic conductor (AMC) structure comprising four different unit cells. This design feature ensures uniform coverage and reception across breast tissue, critical for early-stage tumor detection. Operating in the 2.9 GHz to 7.0 GHz frequency band, the antenna integrates a back-plane reflector that helps increasing the gain by 3 dB while enhancing bandwidth at low frequencies, thereby improving directivity and front-to-back ratio. The proposed antenna achieves a peak gain of ~8.1 dBi with the AMC. Furthermore, our antenna exhibits a nearly constant radiation pattern across 93% of its operating bandwidth. These characteristics highlight the antenna suitability for applications such as diagnosis of breast carcinoma and microwave imaging.

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