Study On The Quasi-Optic System For Dielectric Measurements And Related Themes About Bioelectromagnetics

This dissertation probes into the design and manufacture of the quasi-optic resonator system for measuring the complex dielectric constant in millimeter wave range and relevant themes about dielectric in bioelectricmagnetic. Several theoretical and experimental results which bring forth new ideas are achieved and listed as thefollowing:1) Based on Mode-Matching method,the coupling between waveguide and hemispherical quasi-optical resonator through a slot is analyzed. Further more, the funtions between the resonator's structure parameters such as calibre of the mirror,curvature of the spherical mirror ,length of the resonator and the resonator's microwave characters such as resonant frequency, quality factor, fresnel number are discussed in detail. Serveral aspects including the coupling slot's size of hemisphere quasi-optic resonator are discussed theoretically and calculated systematically, According to the theoretical analysis, an 8mm hemisphere resonator is designed. By making use of HFSS, numerical simulation about the designed prototype is also carried out, the analytic results are consistent with simulation result.2) The complex permittivy measurement system at 8mm millimeter wave band consisting of hemisphere open resonator and scalar network analyzer is developed. The resonant mode numbers are identified by comparing the measured resonance curve and the theory result, the quality factors of the resonator are studied by the theory and experiments. The uncertainty of this system is also analyzed in detail, and then, frequency variation method and cavity length variation method are compared and we deduces that the frequency variation method can reach high measurement precision easier.3) Beginning with the dielectric measurement problem via the hemisphere quasi-optic resonator system,we demonstrate the dielectric measurement theory step by step and discriminate right from wrong among the reports available. The complex permittivity of cell culture dishs, purified base powder are measured by the quasi-optic open resonator system. Perturbation technology are developed with this quasi-optic system, the complex permittivity of graphite powder, carbon nanotube are measured by this new method and compared with the results of waveguide method.4) By analyzing the electromagnetic wave scattered by a mutilayed biology cell model according to the biologist and biochemist's reports about...