Automated design of a three-dimensional fishbone antenna using parallel genetic algorithm and NEC

A new antenna configuration, named the three-dimensional fishbone antenna (3DFA), as an improvement of the conventional fishbone antenna, is presented in this letter. It consists of dipoles that may be of nonuniform lengths with unequal spacing and are allowed to tilt in haphazard directions. To achieve a high endfire gain and good impedance match, the structural parameters of the 3DFA are optimized in an automated design, making use of the genetic algorithm (GA) in conjunction with numerical electromagnetic codes (NEC) and cluster parallel computation. The design results are presented and discussed. A prototype of such designed 3DFA has been fabricated and tested. The measured radiation pattern and the return loss of the antenna are compared with the computational results, and a good agreement is observed. Another such designed 3DFA has achieved an endfire gain up to 16.72 dBi, which surpass the maximum gain of a conventional Yagi-Uda antenna with the same number of elements by 87%.