Copyright ©2017, IGI Global. Copying or distributing in print or electronic forms without written permission of IGI Global is prohibited. DOI: 10.4018/978-1-5225-2322-2.ch005 Chapter 5 115 Collective-Animal- Behaviour-Based Optimized Null Placement in Time-Modulated Linear Antenna Arrays Gopi Ram MITS Madanpalle, India Rajib Kar NIT Durgapur, India Durbadal Mandal NIT Durgapur, India Sakti Prasad Ghoshal NIT Durgapur, India ABSTRACT In this paper optimal design of time modulated linear antenna arrays (TMLAA) with optimal placement of nulls in the desired direction of elevation plane has been dealt with the approach based on evolutionary algorithm like collective animal behaviour (CAB). Analysis has been done in theoretical and practical environment. Firstly the current excitation weights of the linear array of isotropic elements have been optimized by CAB is applied to improve null performance of TMLAA by Radio Frequency (RF) switch in MATLAB environment. The nulls positions of a TMLAA can be reduced sig- nifcantly by optimizing the static excitation amplitudes and proper design of switch-on time intervals of each element. The CAB adjusts the current excitation amplitude of each element to place deeper nulls in the desired directions. Secondly the obtained optimal current excitation weight of the array factor is practically implemented in computer simulation technology- microwave studio (CST- MWS) environment. The array of microstrip patch antenna has been designed to operate at 5.85 GHz.