Improvement of antenna return loss using binary particle swarm optimization method

Abstract

The efficient transfer of energy, the impedance of the antenna and transmission cable connecting them must be the same. Antennas and transmission lines are typically designed for 50 Ω. In the case of antenna has an impedance different than 50 Ω, then an antenna is mismatched. Accordingly, the way of improving mismatch of antenna is reducing return loss value (S <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">11</sub> ). The shape of the different antennas affects to a return loss (S <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">11</sub> ). This paper presents a method for the reduction of antenna's return loss using changing of antenna's shape and search optimize a shape with binary particle swarm optimization (BPSO). In the process define three fitness conditions, which optimize return loss at a dual frequency are 2.4 and 5 GHz, second and third fitness optimize at a single frequency are 2.4 and 5 GHz, respectively. The results from the dual-band optimizing return loss are -37.73 dB and -17.16 dB, for single-band antenna at 2.4 GHz, the results of return loss are -17.34 dB and -2.3 dB, and the last fitness condition for the single-band antenna at 5 GHz are -15.11 dB and -31.44 dB. The first fitness condition supports IEEE 802.11 a/b/g standard, That the designed patch antenna can operate at both 2.4 and 5 GHz.