Development of a QMSIW Antenna Sensor for Tumor Detection Utilizing a Hemispherical Multilayered Dielectric Breast-Shaped Phantom

In this article, a compact, lightweight, quarter mode substrate integrated waveguide (QMSIW) cavity-backed antenna is proposed as a near-field microwave sensor for breast tumor detection operating in the ISM frequency band. The proposed sensor exhibits excellent responsiveness in identifying anomalies in the dielectric characteristics of breast tissues. First, a QMSIW cavity-backed antenna is designed which operates at 2.78 GHz and then a complementary split ring resonator (CSRR) slot is etched on the patch of the antenna near the magnetic walls resulting in a shift of the resonant frequency to 2.6 GHz. The slot plays a crucial role in achieving miniaturization while maintaining the same sensitivity as the antenna sensor. The proposed antenna is fabricated on RT Duroid 5880 and the overall footprint of the antenna is 0.38 x 0.3 lambda(1). An experimental validation of the sensor is performed following the preparation of realistic heterogeneous breast phantoms, both with and without a tumor. Initially, the sensor's performance is examined over the healthy breast phantom and then subsequently evaluated by systematically altering the location and radii of the tumor. The simulated and measured S-11 results exhibit a notable disparity between healthy and malignant tissues. Additionally, a specific absorption rate (SAR) analysis is conducted to examine the differences between healthy breast tissues and malignant tissues. Furthermore, a power loss analysis was performed to evaluate the magnitude of reflected and attenuated EM waves in various female breast tissues.