V.M. Khokhlov, E.O. Chernet

For the solution of problem in the region of antenna design and tests of technical equipment for the electromagnetic compatability are the multifunctional anechoic chambers and the screened accommodations, coated by the above-wide-gamut absorbers of the electromagnetic waves, which are made from the materials which possess dielectric or(and) magnetic losses. Pyramidal absorbers with the dielectric losses have many merits in comparison with the ferrite absorbers, however, their height must be commensurate with the wavelength of low-frequency operating range. The decrease of the overall height of pyramidal absorbers for an increase in the effective area chambers is urgent and complex problem. The analysis of the results of numerous studies and experiments showed that the expansion of low-frequency range for pyramidal absorbers is possible due to a notable increase in the absorbing properties of basic material with additional matching of the front boundary of absorber with the parameters of free space. A notable increase in the absorbing properties for absorbers, manufactured on the basis of polyurethane foam, is completely problematic, since the application of the carbon-containing fillers hampers obtaining fine-pored structure, is decreased price formation, which leads to an increase in material density and, as a result, to an increase in the reflection coefficient. Progressive direction in this region is the use of hull absorbers, whose pyramidal containers can be filled with the absorbing materials with different radiophysics parameters, attaining in this case the required values of reflection coefficient in the assigned frequency band. The authors found the technical solutions, described in the patent for the invention RF of № 2359374, because of which became possible the expansion of frequency range absorber. On the basis of [ekovaty] and carbon fibers evenly distributed in it were developed friable materials with different absorbing properties, with which then the pyramidal containers in layers were filled. Initially it was developed by absorber with maximally absorbing fillers, which made it possible to considerably enlarge operating range at the low frequencies. Then, due to the use several discharged matching able upper layer of filler, to accomplish soft agreement absorber with the incident electromagnetic microwaves. The obtained versions absorbers on basis materials with the increased dielectric losses and the matching able layers showed positive results. Working wavelength range of different in the height optimum versions absorber «Universal-Delta» it increased two and, for example, with the height of construction 58 cm it has at the frequency of 100 MHz reflection coefficient minus 14 dB with the subsequent decrease to minus 45 dB in the range frequencies to 40 GHz. On the basis obtained results it follows that the selected direction of obtaining above-wide-gamut absorbers is promising and makes it possible to decrease the height of pyramidal absorbers, increasing the area of accomodations. Furthermore, taking into account economic expediency, the presence of a dimensional number of developed above-wide-gamut absorbers makes it possible to on their basis create universal multifunctional anechoic chambers, in which is possible the solution of problems both in the region of antenna design and in the region test of technical equipment for the electromagnetic compatability.