A Fractal Antenna Design for Microwave Radiology Imaging Applications

In this paper, a compact, multiband, and unidirectional microstrip patch antenna based on an H-Tree fractal slots structure loaded with a metallic reflector has been introduced for Microwave Radiology Imaging systems. The antenna structure consists of a 70.70×56mm
²
rectangular patch printed on 173×173×1.6mm
³
FR4 substrate. the metallic reflector was used to reduce the back lobes by directing the antenna radiation patterns toward the boresight to improve the antenna gain. The proposed antenna was fed by a 50 $\Omega$ microstrip line. A commercial software package was invoked to simulate the antenna performance and test the design using CST Microwave Studio. It was found that the suggested antenna shows multiband at resonance frequencies: 0.984GHz, 1.422GHz, and 1.722 GHz. The suggested antenna offers a total reduction size of about 75 %. Finally, the antenna achieves a maximum gain of 7.45 dBi with gain variations less than 2 dBi over the bands of operation and peak FBR at about (21) dB.