Couplet numerical — Experimental method for frequency and temperature dependences of biological materials dielectric properties investigation at microwave frequencies

The article focuses on the measurement and calculation of dielectric properties of biological tissue in the frequency band 4,5 GHz-6 GHz. Special attention is paid to the frequency and thermal dependence dielectric constant and loss factor. Observed frequency changes of biological tissue dielectric properties obey causality, i.e. Kramers-Kronig relationships which relate changes of dielectric constant with conductivity changes. Our results for frequency dependence of complex permittivity prove the fundamental Cole-Cole model but also the necessity to investigate the biological tissues like heterogeneous material with not only one relaxation phenomena. The computed data are compared with measured total frequency response of biological tissue.