Coaxial Slot Antenna Array Design for Microwave Ablation and Monitoring

Tracking the ablated region in real-time can be advantageous during microwave ablation. In this study, an antenna array that ablates the tissue and monitors the ablation process is proposed. Monitoring is realized by tracking the coupling between the array elements which changes during ablation. That is because the permittivity and conductivity of organic tissues depend on temperature. The proposal is demonstrated through a hepatic tumor example with cascaded thermal and electromagnetic simulations. As the array element, a coaxial slot antenna is designed to operate at 2.45 GHz. The temperature-dependent permittivity and conductivity values are calculated through thermal simulations which contain both healthy and malignant tissues. It has been shown that the application of ablation with an output of 10 W per antenna causes a considerable change in coupling. A 100 MHz shift in frequency and 2.5 dB change in magnitude have been observed after 300 seconds.