M.V. Davidovich

The radio waves and microwaves are widely used for control of biological tissue properties and hyperthermia of malignant tumors. There are different near field applicator antennas which are used for this purpose. In the present paper the waveguide probe in the form of rectangular waveguide section with the flange which is radiating into the flat multilayered medium has been considered. This medium is corresponds to three-layered biological tissue with typical parameters of skin coverlet, hypodermic fatty layer and thick muscular layer in which the object with heightened water factor may be disposed. This is typical for cancerous formations. It is expedient to fill up the probe by distilled water or by alcoholic-water solution for matching and size reduction, and to isolate the flange by thin dielectric plate. The Green-s function and the volume integral equation for considered structure have been constructed and the general disclosure problem for contrast dielectric object therein has been formulated in this paper. The disclosure problem means the recognition of the object presence, its form, position and properties. There are typical problem of ambiguity in general formulation of inverse problems. The more simple location problem is numerically investigated in the paper. It is based on two-dimensional scanning and detection of center coordinates for anomalous reflection coefficient region. The dielectric object detection (or location) possibility has been shown theoretically by probe scanning if its dielectric properties (or water content) sufficiently differ (about 15-20%) from environment. Such differ is fully determined experimentally up the noise level of S-parameters analyzer. The typical object dimension may be in several times smaller than the probe wide wall dimension when the probe is filled by water or by water solution. The sensitive reflectometers and the matched probes must be used to increase the resolvability, including the usage the probes with small narrow wall dimension and with the iris aperture. Also the passive and active location with the noise filtration may be used. The general disclosure problem implies the form recognition and identification that demands the experimental data redundancy. The numbers of numerical operations both for direct and inverse problem solutions have been estimated for volume integral equation formulation.