Wideband circular polarized binomial antenna array for L-band radar

Abstract

This paper presents a compact binomial rectangular patch antenna array with wide bandwidth and circular polarization for the L-band radar application operating at the frequency of 1.35 GHz. A 16-element planar antenna array is designed with independent coaxial feed to each element which helps in reduction of negative effects of complex feed network on antenna performance. The patch elements are truncated diagonally which is useful in producing circular polarization. There is an air cavity in between the ground plane and substrate which helps in improving the gain of the antenna and the cumulative effect of the truncated patches and the air cavity will increase the bandwidth of the antenna. The inter-element spacing in the antenna array is considered as half of the free space wavelength. The antenna elements are fed with nonuniform amplitudes to reduce the side lobe levels which are a major problem in radar applications for this Pascal triangle coefficient are considered for feeding the antenna elements.