COMPLEX RELATIVE PERMITTIVITY EXTRACTION TECHNIQUE OF BIOTECHNOLOGY MATERIALS IN MICROWAVES DOMAIN

We have established a test fixture and procedure to extract dielectric complex permittivity for biotechnology materials, especially those used in medical (human tissue and liquid 900MHz), environmental domains (i. e., raffia palm trees, spring water) and food (semolina and polenta) in microwave domains. Two circular coaxial transmission-lines have been designed, manufactured and presented in this paper to reach main goals. The technique is based on the use of the transmission-line propagation constant. This technique is broadband, easy to implement and no need to use the form-factor during the computational procedure. The test-designed fixture has made to ease its filling with sample to characterize. The use of the wave cascade matrix to solve discontinuity effects is applied through two different transmission line lengths with identical geometries. That's the way we solved discontinuities and pointed out mathematical formula limits. This apparatus offers the equipotentiality of the electric field and can be used to measure liquid, mud, gunpowder and granulate materials, but it needs buffering wafer samples. All samples used in this apparatus are supposed non-magnetic, and our study has been approved only when the Quasi TEM-mode is propagated.