Near-Field Measurement System for 5G Advanced Antenna System at mm-Wavelength

Abstract: An antenna is one of the most fundamental elements of wireless communication systems. The radiation behavior of antennas is characterized with the aid of the farfield radiation pattern. In this thesis, a near-field antenna measurement system is designed to predict the far-field pattern of antenna operational frequency 28 GHz and 39 GHz. The near-field measurement system operates by measuring magnitude and phase of the tangential electric field components radiated by antenna under test over a surface in an anechoic chamber and then mathematically transforming using the MATLAB tool into the far-field radiation pattern. The WR28 standard gain horn antenna is used as an antenna under test and WR28 rectangular waveguide as a probe. The planar scanning geometric was implemented by designing a scanner of length 165 mm x 175 mm and near-field data are measured at specific points based on the sampling values using a Vector Network Analyzer (VNA) in an anechoic chamber. The near-field to far-field transformation is implemented using the Plane Wave Spectrum (PWS) method by Fourier transforms in MATLAB. The measurements were performed for different separation distances between the antennas, sampling value, and reasonably accurate results are observed.