High selectivity and sharp roll-off filtenna array for Ku-band application

Abstract

ABSTRACT A (1 × 2) filtenna array inspired by an inter-digital-based bandpass filter is presented in this paper for simultaneous radiation and filtration. The feed line of the proposed antenna array resonating at 14 GHz with fractional bandwidth of 5.72% is modified in such a way that it acts like an inter-digital-based bandpass filter. The equivalent lumped circuit model of the proposed structure is analysed and detail synthesis procedure is presented. To study the impact of dimensional variations on the performance of proposed filtenna array, various parametric studies of filtenna and corresponding antenna array are performed and compared. The design strategy involves (N-1) filter circuits for realising a (1 × N) element filtenna array. The proposed array exhibits advantageous features such as low circuit complexity, compact size and low operational power over other reported filtenna arrays. The presented filtenna possesses fractional bandwidth and peak gain of 3.85% and 8.14 dB respectively at resonating frequency of 14 GHz, which covers the standards of Ku-band. The physical size of the filtenna array in terms of free space wave length is 1.96λ0 × 1.96λ0 × 0.073λ0 at 14 GHz. The radiation patterns are omni-directional in E-plane and nearly omni-directional in nature at H-plane at resonance frequency of 14 GHz.