Design of a Compact Flexible Microwave Vivaldi Antenna for Medical Imaging

The research work offers a compact double slot Vivaldi antenna of size 50 X 40 X 0.4mm<sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">3</sup> has two resonant frequencies 2.03 and 6.33 GHz. It designed on top of polyimide substrate of the thickness 0.4mm and dielectric constant of 3.5 with microstrip on the bottom side through which element are excited. Compared to the single slot Vivaldi antenna the proposed antenna provides wider bandwidth and exhibit more controlled radiation patterns. VSWR for the recommended antenna at frequency 2.03 GHz is 1.35 and at frequency 6.33 GHz is 1.25. An array of four same antennas is surrounded the breast phantom at equal distance which operates in frequency range 1.5-7.5 GHz and designed on Computer simulation technology (CST). Whereas one antenna act as transmitter and other three as receiver and used to detect presence of tumor size 5mm in phantom and the simulation result of reflection coefficient (S<inf xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">11</inf>) of phantom with and without tumor is compared which implies that tumor can be detected by the suggested antenna in a phantom