Title :
Sensing dielectric properties of arbitrarily shaped biological objects with a microwave resonator
Author :
Kraszewski, A.W. ; Nelson, S.O. ; You, T.S.
Author_Institution :
US Dept. of Agric., R.B. Russell Agric. Res. Center, Athens, GA, USA
Abstract :
A rectangular waveguide resonator operating in the H/sub 107/ mode at 6 GHz was used in determining the change in resonant frequency and the Q-factor of the cavity when loaded with single soybean seeds or corn kernels of various shapes and dimensions. By measuring those variables for a kernel oriented in two positions differing by 90 degrees with respect to the maximum electric field vector, the average values of Delta F (shift of resonant frequency) and Delta T (transmission factor) were found to be virtually shape-independent. The ratio Delta F/ Delta T is a size-independent and well-defined function of the material properties ( epsilon \´-1)/ epsilon ", and as such it can be related to the material density, moisture content, or other characteristics when all other properties remain unchanged.<>
Keywords :
bioelectric phenomena; biological techniques and instruments; cavity resonators; dielectric properties of substances; microwave measurement; 6 GHz; Q-factor; arbitrarily shaped biological objects; corn kernels; material density; material properties; maximum electric field vector; microwave resonator; moisture content; rectangular waveguide resonator; resonant frequency; soybean seeds; transmission factor; Dielectrics; Electric variables measurement; Frequency measurement; Kernel; Material properties; Position measurement; Rectangular waveguides; Resonant frequency; Shape measurement; Waveguide transitions;
Conference_Titel :
Microwave Symposium Digest, 1989., IEEE MTT-S International
Conference_Location :
Long Beach, CA, USA
DOI :
10.1109/MWSYM.1989.38699
