NeoScan Featured in Recent IEEE AP Transactions Paper
A new journal article titled “Pattern and Gain Characterization Using Nonintrusive Very-Near-Field Electro-Optical Measurements over Arbitrary Closed Surfaces” authored by K. Sarabandi, J. Choi, A. Sabet and K. Sabet, and published in the February 2017 issue of the IEEE Transactions on Antennas and Propagation, contemplates the unique application of the NeoScan field measurement system as an effective tool for characterization of low frequency antennas with operating frequencies under 50MHz. Building an effective anechoic chamber at the HF frequency band can be a serious challenge due to the very large wavelengths involved (1m – 10m).
Abstract: A nonintrusive near-field measurement technique for 3-D radiation pattern and gain characterization of antennas is presented. The method is of particular interest for low-frequency antennas for which anechoic chambers cannot be developed and far-field measurements are rather cumbersome. Nonintrusive, broadband measurements are performed using an extremely small all-dielectric electro-optical probe to measure the tangential electric fields of an antenna under test (AUT) at a very-near surface enclosing the antenna. Far-field radiation is computed from a new near-field to far-field transformation formulation using only the tangential components of the electric field over an arbitrary surface. This procedure employs reciprocity theorem and the excited electric current on the surface of a perfect electric conductor enclosure having the same geometry as the scanned surface and illuminated by a plane wave. In this way, a full spherical radiation pattern and gain of the AUT are easily computed without expensive computation and truncation errors. To demonstrate the proposed approach, a miniaturized low very high frequency antenna operating at 40 MHz with dimensions 0.013λ0 × 0.013λ0 × 0.02λ0 is utilized. The far-field results from our approach are shown to be in good agreement with those obtained from full-wave simulation and direct far-field measurement performed in an elevated outdoor range