Matching and radiation characteristics of a phased array based on quasi-Yagi planar antennas with an additional screen

Abstract

This article presents the results of numerical investigation and optimization of matching and radiation characteristics for a single planar quasi-Yagi antenna and for a planar phased antenna array (PAA) with size 11×11 elements, which is designed based on these radiators. The research has been performed utilizing the finite difference time domain technique. The calculations have taken into account the presence of an additional metal screen behind the radiating curtain and the feeding of each array’s element via the coaxial-to-microstrip transition, that has made the model of an array as close as possible to the real PAA design and to its performance under real conditions. The levels of electromagnetic coupling between adjacent array elements have been investigated, the variations of operating characteristics of elements in its structure have been demonstrated in the case of in-phase excitation and in the scanning mode. It has been found that the possible scanning sector of this screened PAA falls within the range ±45° for the reflection coefficient of any array’s element, which is less than –10 dB in the frequency range not less than 10%, and for the central element of an array the corresponding operation frequency range exceeds 30% for the scanning in E-plane and it is larger than 17% for the scanning in H-plane.