No abstract

In this paper, a general and easy procedure for designing the symmetrical Wilkinson power divider that achieves equal-power split at N arbitrary frequencies is introduced. Each quarter-wave branch in the conventional Wilkinson divider is replaced by N sections of transmission lines, and the isolation between the output ports is achieved by using N resistors. The design parameters are the characteristic impedances and lengths of the N transmission line sections, and the N isolation resistors. The even-odd modes of analysis are used to derive the design equations. Closed-form expressions, which are suitable for CAD purposes, are derived for the dual-band divider. For N ≥ 3, closed-form expressions are not available, and therefore, the powerful particle swarm optimization method is used to obtain the design parameters. Examples of the dual-, triple-, and quad-band dividers are presented to validate the proposed design procedure, and the results are compared, wherever possible, with published results using other methods.

The goal of this article is to introduce and use the cuckoo search (CS) as an optimisation algorithm for the electromagnetics and antenna community. The CS is a new nature-inspired evolutionary algorithm (EA) for solving Ndimensional optimisation problems. Compared with other nature-inspired algorithms, the CS algorithm is easy to understand and implement and has minimum number of parameters to tune. Different examples are presented that illustrate the use of the CS algorithm, and the results are compared with results obtained using other optimisation methods. Preliminary results suggest that the CS algorithm can in some cases outperform other EAs, at least for the examples studied in this article.

This study presents a comprehensive study of the design and optimisation of linear antenna arrays using the cuckoo search (CS) algorithm. The method is used to control important radiation characteristics of the antenna arrays (such as side‐lobe level, beamwidth, nulls) by optimising the parameters of the array elements (amplitude, phase, and position). Different design examples are presented that illustrate the robustness of the CS algorithm and its ability in achieving the design goals. The considered design examples clearly show that the CS algorithm is a simple and yet a powerful optimisation tool that can be used in antenna array design problems with great confidence.

No abstract