Análise de antenas planares para aplicações médicas nas bandas ISM de 435 MHz, 915 MHz e 2,45 GHz

Abstract

Wireless devices are presented, in the most recent researches, as alternatives for monitoring various medical parameters, with applications in the frequency bands designated for Medical Device Radiocommunications Service - MedRadio (401 - 405 MHz), Medical Implant Communication Services - MICS (402 - 405 MHz) and Industrial, Scientific and Medical - ISM (433 - 435.8 MHz; 902 - 928 MHz; 2.4 - 2.5 GHz), with the possibility of performing invasive and non-invasive analyzes on human tissue or equivalent samples, replacing human tissue. In this dissertation, a parametric analysis of three rectangular antennas is performed, with slits positioned close to the edges of the patch, for sensing. Frequency responses of planar microstrip antennas with medical applications in the ISM band are presented in the three frequency bands (433 - 435.8 MHz; 902 - 928 MHz; 2.4 - 2.5 GHz). The results of the simulations were obtained by the Ansoft HFSS software for resonance frequency, bandwidth, reflection coefficient, specific absorption rate and sensitivity. The measurements were performed with solid samples of pork. A mathematical model was created to characterize the relative permittivity of the samples. The simulated and measured results showed excellent agreement and confirm the possibility of use in medical applications for monitoring and transmitting information, in addition to measurements of meat properties, replacing human tissue.