Title :
Heating characteristics of thin helical antennas
Author :
Mirotznik, Mark S. ; Engheta, Nader ; Foster, Kenneth R.
Author_Institution :
Pennsylvania Univ., Philadelphia, PA, USA
Abstract :
An analytical model was developed to predict the specific absorption rate (SAR) pattern of helical antennas in a general medium. Experimental measurements verified the accuracy of the model and revealed the complicated nature of the heating pattern. The calculated and measured results show a distinct standing wave pattern along the length of the antenna, whose wave number depends strongly on the helical pitch angle. Also, as the conductivity of the external medium increases, the heating pattern shifts towards the antenna´s tip. The immediate motivation of the present study is to design catheters incorporating microwave antennas that can be inserted into the body and used to ablate (destroy by heating) selected tissues.
Keywords :
antenna radiation patterns; biomedical equipment; biothermics; radiation therapy; radiofrequency heating; waveguide antennas; SAR pattern; analytical model; body; catheters; conductivity; external medium; heating characteristics; heating pattern; helical pitch angle; microwave antennas; specific absorption rate; standing wave pattern; thin helical antennas; tissue ablation; wave number; Boundary conditions; Catheters; Conductors; Dielectrics and electrical insulation; Heating; Helical antennas; Magnetic shielding; Predictive models; Transmission line theory; Wire;
Conference_Titel :
Bioengineering Conference, 1992., Proceedings of the 1992 Eighteenth IEEE Annual Northeast
Conference_Location :
Kingston, RI, USA
Print_ISBN :
0-7803-0902-2
DOI :
10.1109/NEBC.1992.285969
