Izračun izračene snage iz rezulata mjerenja u bliskom polju dobivenih metodom uzorkovanja na planarnoj širokoj mreži

A full procedure is developed in this paper for evaluating the power radiated by an antenna under test from a nonredundant number of near-field measurements collected by the innovative planar wide-mesh scanning. It can be applied for the antenna directivity evaluation whenever the power radiated by the antenna in the backward half-space is negligible. Such a procedure makes use of a closed form formula for computing the total radiated power from the knowledge of the radiation intensity samples on the far-field sphere. These samples are determined via a probe compensated near-field — far-field transformation. An optimal sampling interpolation formula is also used for their evaluation. The effectiveness of the proposed procedure is assessed by numerical simulations.U radu je razvijena potpuna procedura za izračun snage koju zrači ispitna antena. Procedura je zasnovana na neredundantnim mjerenjima u bliskom polju na osnovi inovativnog uzorkovanja na planarnoj širokoj mreži. Metoda se može primijeniti za odredivanje usmjerenosti antene u slučajevima kada je zračenje u stražnji poluprostor zanemarivo. Metoda se zasniva na uporabi izraza za izračun ukupne izračene snage preko poznavanja izračene gustoće snage uzorkovane na sferi u dalekom polju. Ti uzorci su odredeni primjenom transformacije iz bliskog polja (kompeziranog zbog utjecaja mjerne sonde) u daleko polje. U predloženoj metodi takoder je rabljena optimalna interpolacijska formula za uzorkovanje. Efikasnost predložene metode razmatrana je numeričkim simulacijama

On the efficient interpolation of stochastic bandlimited signals

Interpolation of stochastic band-limited signals is of relevance both from the theoretical point of view and application purposes. It is well-known that the classical interpolation method for band-limited signals, which follows from the Whittaker-Kotel'nikov- Shannon sampling theorem, provides the appropriate answer to exactly reconstruct them. Unfortunately, whenever an open domain is in question, only truncated versions of cardinal series expansions can be employed and this generates artifacts on the interpolated data. In particular, the quality of the interpolation scheme affects the data statistics and is a relevant issue which must be carefully examined. An interpolation scheme, which minimizes statistical artifacts, is therefore of great interest. In this paper we propose the use of two efficient interpolation schemes and demonstrate that they provide much better results than the truncated cardinal series expansion