Frequency Reconfigurable Antennas Design for Cognitive Radio Applications with Different Number of Sub-bands Based on Genetic Algorithm

This paper proposes frequency reconfigurable antennas using genetic algorithm, suitable for cognitive radio applications. The optimization is applied to find the slot shape and the switches locations in the ground plane of monopole antennas for adjustment of the bandwidth. We introduce a new cost function appropriate for designing antennas for cognitive radio applications. In the first design, the presented antenna can operate in the band of 1.9-3.8 GHz and two sub-bands 1.8-2.78 and 2.78-3.8 GHz using the possible minimum number of switches. In the second design, the proposed antenna works in a wide operating band of 1.85-4 GHz and three different sub-bands 1.72-2.27, 2.27-2.9 and 2.9-3.75 GHz. The proposed antenna with three modes of operation is fabricated and the comparison of the simulated and measured results shows a good agreement.