Radial Waveguide with Enhanced Exposure Volume for In Vivo Experiments Involving Many Large Rodents

摘要

Radial waveguide systems are suited for exposure of large numbers of samples at radio and microwave frequencies. An application of current interest is the investigation of biological effects on rodents being exposed "in vivo" to mobile communication signals. A problem arises if the cross sectional dimensions of the waveguides have to exceed half a wavelength as a consequence of the size of the biological objects. Then higher order waveguide modes are able to proagate contributing to uncontrollable fluctuations of the exposure field. Two concepts for suppressing the influence of disturbing modes in such cases are discussed. These measures were applied to an exposure system for experiments with 24 Wistar rats at 890 MHz. The field deviation across the entire volume of the cages turned out to be less than 13