Abstract: One method of cancer therapy is to utilize nano-antenna for thermal ablation. In this method, the electromagnetic waves emitted from the nano-antenna are absorbed by the tissue and lead to heating of cancer cells. If temperature of cancer cells reaches a threshold, they will begin to die. For this purpose, an L-shaped frame nano-antenna (LSFNA) is designed to introduce into the biological tissue. Thus, the radiation characteristics of the LSFNA such as near and far-field intensities, directivity, and sensitivity to its gap width are studied to the optimization of the nano-antenna. The bio-heat and Maxwell equations are solved using the finite element method. To prevent damage to healthy tissues in this method, the antenna radiation must be completely controlled and performed carefully. Thus, penetration depth, special absorption rate, temperature distribution, and the fraction of tissue necrosis are analyzed in the biological tissue. That is why the design and optimization of the nano-antennas as a radiation source is important. Also, a pulsed source is used to excite the LSFNA. Furthermore, focusing and efficiency of the nano-antenna radiation on the cancer cell is tuned using an adjustable liquid crystal lens. The focus of this lens is changing under an electric field applied to its surrounding cathode.

Key words: cancer therapy, directivity, far-field intensity, hyperthermia, liver cancer, nano-antenna, thermal-ablation, tunable liquid crystal lens