PROJECT TITLE :

A Balun-Free Helical Antenna for Minimally Invasive Microwave Ablation

ABSTRACT:

We tend to present a balun-free coax-fed helical antenna for microwave ablation. The proposed antenna produces a localized specific absorption rate pattern at the specified frequency of operation while not using a coaxial balun. This reduces the outer diameter of the antenna and, therefore, its invasiveness. Balun-free operation of the proposed antenna is achieved by operating the helical antenna at the second resonant frequency of the helix where a current minimum occurs at the feed point, resulting in an intrinsically high feed-purpose impedance. This efficiently chokes the currents excited on the outer surface of the feeding cable. Using a compact quarter-wavelength impedance transformer or a coaxially implemented pi network of reactive components at the antenna feed purpose, we tend to achieve an wonderful impedance match between the antenna and the main feeding line. We tend to fabricated a prototype of the proposed helical antenna with an outer diameter of 2.two mm using the pi matching network. We tend to used this prototype to conduct ablation experiments in ex vivo bovine liver. The scale of the ensuing ablation zones are almost like those produced by coaxially fed antennas that use coaxial baluns. Our balun-free antenna design offers a promising answer for reducing the invasiveness of interstitial antennas used in microwave ablation.