NEAR – FIELD COHERENT EFFECTS AT THERMAL MICROWAVE RADIATION RECEIVING ON COUPLED LINEAR WIRE ANTENNAS
Y. N.
Barabanenkov1, M. Yu. Barabanenkov2, V. A. Cherepenin1
1 V.A. Kotelnikov Institute
of Radioengineering and Electronics of RAS, Moscow
2 Institute of Microelectronics Technology of RAS, Chernogolovka
Received December 4, 2011
Abstract. We apply to study coupled receiving antennas a theory of electromagnetic
wave multiple scattering by ensemble of dielectric and conductive bodies, with
describing the excited currents inside bodies in terms of electric field tensor
T-scattering operator. A system of equations for currents on surfaces of
coupled perfectly conductive receiving antennas is written with the aid of a
single antenna surface T-scattering operator. This system is resolved for the
case of coupled linear wire receiving antennas in the form of thin vibrator-dipoles
when asymptotic method of “big logarithm“ leads to separable wire T-scattering
operator of single tuned vibrator-dipole. The separability simplifies analytic
evaluating the local total currents on two (and more) coupled receiving
antennas and get a dimensionless coupling factor. Our final aim consists in using
the obtained analytic solution to study near field coherent effects caused by thermal
microwave radiation incident electric field distribution along single or two
coupled receiving vibrator-dipole antennas placed at a heated biological object
boundary surface and tuned to half wavelength in the object. In the case of equilibrium
thermal radiation we meet a generalized Nyquist formula for currents’ fluctuations
excited on coupled receiving vibrator-dipole antennas, with accounting the
auto-correlation and cross-correlation functions of random electric field inside
each antenna and on both antennas, respectively. In the case of local volume change
of the biological object temperature distribution we reveal in the model
framework of random electric dipole source inside object absorption skin slab
area the interference-extreme properties for fluctuations of currents excited
along antennas depending on relative positions of antennas and random electric
dipole source. The reveled extreme properties are used as base to reconstruct the
random electric dipole position via scanning the single antenna or two coupled
ones along biological object boundary surface.
Key
words: receiving coupled antennas, excited
currents, T- scattering operator, thin vibrator antennas, biological object,
temperature local variation, thermal radiation, interference receiving fields,
scanning local random source.