PROGETTO DI METAMATERIALI PER APPLICATORI MEDICALI A MICROONDE

The aim of this thesis is the improvement of the focusing effects of the electromagnetic field irradiated by a microwave needle applicator in the biological tissue by using lenses based on metamaterials, in order to obtain a more efficient tumor thermal therapy. The needle applicator works in the Industrial, Scientific and Medical (ISM) band at the frequency f=2.45 GHz. In this thesis two metalenses have been designed by using the software CST Studio Suite®. The former has given worse results than the applicator without metalens. The simulated minimum of the modulus of the scattering parameter |S_11 | of the needle applicator with the first metalens at the frequency f=2.45 GHz is greater than that of applicator without metalens. The power absorbed by the tumour and epatic tissue is lower than in the case without metalens. The latter metalens has given better results, in fact the minimum of the modulus of the scattering parameter |S_11 | has not changed, but the quantity of electromagnetic power absorbed by the tumour is higher and the quantity of power absorbed by the epatic tissue is lower than the original case. Therefore, the performance of the treatment has been improved by using the second metalens. This work could be the start of new projects of metalenses for more efficient thermal applicators.