Utilization of radiometric methods of antenna parameters measurements in millimeter wave band

At creation of microwave radiometric systems intended for remote sensing applications detailed estimation of antenna properties regarding the values of loss factor and beam efficiency is one of actual metrological tasks. Similar researches have especial meaning in millimeter-wave band at creation of high-gain single-beam or multi-beam antenna systems, because at that frequency band receivers aren\´t capable provide yet low-noise inputs and thus realized antenna parameters substantially depend on radiometric remote sensing system final quality on the whole. When antenna loss level and beam efficiency (beam scattering rate) are estimated in microwaves, wellknown radiometric methods of measurements can be used as a main technique, that based on consecutive radio brightness temperature registration for distributed radiation sources "covering" receiving radiometric system together with antenna in complete solid angle 4π, and also the sources overlapping main beam footprint and placed in far, or near field zone. Clear sky thermal radiation from zenith observation angles can be used as wide-band natural isotropic noise source. In this case, measurements need to be carrying out in some specific conditions on open area that must be chosen from requirements of absence of shadings from external constructions (for example, on a roof of a building), that is difficult enough guarantee during researches, taking into account corresponding complexity of the works and time-dependent meteorological situation (clouds, wind, precipitation). The problem of high functional quality realization for scanning multibeam antenna, in main for its loss factor and beam efficiency, has made the important component of the researches carrying out at W-band radiometric system design intended for customs service applications.