Reflective array with controlled focusing for radiotomographic application

It's considered the principle possibility of creation the managed reflectors for formulation of given field distribution in the focus area. Reflectors change the reflect ratio in dependence of the external control. The proposed theoretical modeling of such controlled focused device which provides focuse to a specific point in a given distribution of the reflectors. On the basis of numerical simulation it's considered the application of this approach for the solution of the problem of radiotomography

Radiotomographic system construction on the basis of multi-elemental reflective array

The authors propose a solution of the problem of radiovision using the reflective array, each element of which can change the reflection coefficient under the action of external control voltage. The focusing abilities of flat reflection array of monochromatic radiation were studied to solve the problem of radiovision. The array element based on waveguide with a controlled reflection coefficient was developed. The phase shift switching is 180°

Remote ultra-wideband tomography of nonlinear electronic components

The efficiency of using ultra-wideband (UWB) signals for nonlinear radar is investigated. In the case at hand, it is necessary to see, based on scattered field disturbances, whether nonlinear inclusions are present in the field of view. The solution suggested is to compare the shapes of UWB signals reflected from the probe area under two conditions: an additional generator irradiating the probe area by intense monochromatic radiation is switched on and off. If a nonlinear electronic component is present in the probe area, the reflected UWB signals differ in shape. Thus, the difference in the shapes of the signals indicates the presence of a component with a nonlinear characteristic

Complex sequrity system for premises under conditions of large volume of passenger traffic

Subsystems of the design of a complex security system for premises under conditions of large volume of passenger traffic are considered. These subsystems provide video- and thermal imaging control, radio wave tomography, and gas analysis. Simultaneous application of all examined variants will essentially increase the probability of timely prevention of dangerous situations with the probability of false alarm as low as possible. It is important that finally, this will provide protection of population and will facilitate the work of intelligence services

Fresnel flat reflector with focusing capability

Theoretical modeling of a Fresnel flat reflector for focusing radiation in the point near the reflector is discussed in this paper. It shows that the reflector calculated for one frequency and one focus position can also be used for other frequencies, but a focusing point should be shifted along a focusing line. Fresnel reflector can be used for a space-frequency filtration in a wide frequency range

Subsurface radiolocation tomography of cables under dual-polarization probing

It is proposed to use the tomographic approach to the problem of detecting and imaging concealed utility networks. This approach is based on generating the three-dimensional radio images of the space being explored from the results of measuring its location wave projections in a dual-polarization measurement mode. The problem is solved by focusing radiation first on the “air–dielectric” interface and then inside the dielectric. Experimental data processing results and reconstructed threedimensional radio tomograms are provided for a “twisted pair” cable and a fiber-optic cable with no metallic inclusions. The results confirm the operability of the approach

UWB tomosynthesis of objects in mediums with metal inclusions

Radiowave tomography of dielectric objects containing metal inclusions is a rather complex problem, since the scattering of waves by dielectric inhomogeneities occurs against the background of substantially stronger reflections from metal parts, even if they are geometrically small. The arising features of obtaining a tomogram in such conditions, including overcoming of disguising by reinforcing ribbons and the appearance of locational shadows at different depths, are discussed in the paper. Herewith principled importance to achieve high focusing of UWB radiation by tomosynthesis is noted on the basis of direct experimental data

Reflective array with controlled focusing for radiotomographic application

It's considered the principle possibility of creation the managed reflectors for formulation of given field distribution in the focus area. Reflectors change the reflect ratio in dependence of the external control. The proposed theoretical modeling of such controlled focused device which provides focuse to a specific point in a given distribution of the reflectors. On the basis of numerical simulation it's considered the application of this approach for the solution of the problem of radiotomography

Remote ultra-wideband tomography of nonlinear electronic components

The efficiency of using ultra-wideband (UWB) signals for nonlinear radar is investigated. In the case at hand, it is necessary to see, based on scattered field disturbances, whether nonlinear inclusions are present in the field of view. The solution suggested is to compare the shapes of UWB signals reflected from the probe area under two conditions: an additional generator irradiating the probe area by intense monochromatic radiation is switched on and off. If a nonlinear electronic component is present in the probe area, the reflected UWB signals differ in shape. Thus, the difference in the shapes of the signals indicates the presence of a component with a nonlinear characteristic