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In this paper, the variation of side lobe level (SLL) of ‘optimized uniformly excited time-modulated linear antenna array’ (OUE-TMLAA) with different number of antenna elements is presented. To realize the optimized array patterns of the arrays, sideband levels (SBLs) is suppressed to below −30 dB and the increase on first null beam width (FNBW) is restricted within 35% of that of the ‘uniformly excited...
A novel approach using Differential Evolution (DE) is proposed for linear array failure correction. In presence of the failure of array elements, only the inter-element spacing's between the array elements are adjusted to regain the pattern closed to the original one. The proposed approach is a cost effective method as no additional attenuators or phase shifters are required. A fitness function has...
In several applications such as wireless communication, radar; shaped beam patterns are used to radiate power in a desired sector of region while suppressing the power towards the other direction to avoid interferences. This paper introduces a new technique to synthesizing flat-top shaped power pattern in time-modulated unequally spaced linear arrays (TMUSAs). Since, TMUSA synthesis problems are multimodal,...
This paper presents a new technique to reduce side lobe levels (SLLs) and side band levels (SBLs) in time modulated antenna arrays (TMAAs) by optimizing discrete values of static excitation amplitudes and continuous values of on-time duration of the antenna elements. The particle swarm optimization (PSO) technique has been utilized to suppress SLL and maximum of SBL (SBLmax) to a pre-defined desired...
In this paper, sideband radiations which are generally regarded as the undesired effects of time-modulated antenna arrays (TMAAs), are exploited to design multi-beam antenna arrays. Time modulation (TM) is applied into uniformly excited linear array of half wave dipole radiators to generate low side-lobe sum and difference patterns at the center frequency and first sideband respectively while the...
In this work, the effectiveness of a relatively newly developed optimization algorithm, artificial bee colony (ABC) algorithm has been employed to synthesize uniformly excited, non-uniformly spaced, symmetrical linear arrays. ABC is used to reduce the side lobe level (SLL) of uniformly excited linear antenna arrays by taking the element spacing as the optimization parameters. The effectiveness of...
In this paper, a cosecant squared shaped beam pattern is synthesized from a uniformly spaced but nonuniformly excited linear antenna array where the uniform spacing of the array elements is considered as half of the desired signal wavelength. The shaped beam pattern is synthesized for the angular beam width of 32° by reducing the side lobe level (SLL) to −20.06 dB and almost without any ripple in...
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