A COMPARATIVE-STUDY OF 4 OPEN-ENDED COAXIAL PROBE MODELS FOR PERMITTIVITY MEASUREMENTS OF LOSSY DIELECTRIC BIOLOGICAL-MATERIALS AT MICROWAVE-FREQUENCIES

A comparative study of four open-ended coaxial probe models which rela te the coastal line end impedance to the complex permittivity of the m aterial under best is presented. The accuracy of the models in measuri ng lossy dielectric/biological material and their robustness as a func tion of the calibration materials are investigated. The four open-ende d coaxial probe models studied are: capacitive model, antenna model, v irtual line model, and rational function model. Experimental results t aken on saline solutions as lossy materials are obtained for the four models.