Design and fabrication of crossed Yagi antennae for dual frequency satellite signal reception at ground

Abstract

<span style="mso-fareast-font-family:Calibri" lang="EN-GB">Design and fabrication of two crossed dipole Yagi antennae have been accomplished with an aim of estimation of total electron content (TEC) through Faraday rotation technique from satellite signal in VHF/UHF band received at ground. The design simulations for 3 and 5 elements crossed Yagi were performed by multiple iterations and optimization through a latest version of an established numerical electromagnetic code (NEC). First, design parameters were calculated and then optimization schemes were tailored to achieve the requisite performance from the crossed dipoles. Some of the most important aspects for Yagi antenna, like radiation characteristics for forward and backward gain, input impedance, bandwidth, front to back ratio and voltage standing wave ratio (VSWR) of a typical 3 and 5-element antenna have been analyzed. Following the successful software design, a step-wise precise hardware fabrication was taken up. Mechanical drawings were made for achieving mm level accuracy in fabrication. Also, thin aluminum tubes were used that matched precisely with the designed parameters and lengths of elements. The impedance matching in hardware fabrication was achieved by connecting Baluns of exact calculated lengths and of particular cable type. Finally, RF characterization was performed. Both the crossed Yagi antenna passed the basic tests that could be crossed checked with software design. The results from each stage of this process have been given with analysis and elemental details. This paper will be a practical guide for in-house fabrication and also a ready reference for interested researchers and students for making a satellite signal receptor in VHF/UHF band at ground.

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