Full-wave simulation, design and implementation of a new combination of antenna array feed network integrated in low profile microstrip technology

Abstract

In this paper, a new modified combination of antenna and array feed network integrated in low thickness microstrip technology is presented. A concept similar to the concept of coherently radiating periodic structures is used to feed a 4-element antenna array. In the feed network, a new combination of Gysel-based 3 and 5 port components as power dividers/combiners is employed to propagate the power into the antenna array so that the desired Gaussian-like amplitudes and linear phase distributions can be obtained. These multi-port components are modified to design the feed network by single-layer microstrip technology without the matching and isolation circuits and through-substrate vias. Therefore, the manufacturing cost and difficulty and design complexity are reduced, considerably. Full-wave simulations of the feed network, unit cells and the final integrated antenna array are done, step by step and the results considering all possible losses are presented. To validate the designs, two prototypes, first the feed network and second the integrated module including both antenna array and feed network designed at 3.5 GHz were fabricated and measured and the S parameters (amplitude and phase) were compared with the full-wave simulations. A good agreement between the results including impedance and radiation characteristics is shown.