**3. Conclusion**

This work looked at the issue of sidelobe level in antenna array and the challenge in reducing the sidelobe level, providing a way the issue and challenge can be overcome. Related literatures were reviewed, different antenna arrays listed, issues and challenges presented, and solution to the issue of sidelobe level outlined, with graphs. This work has shown that enhanced firefly algorithm (EFA) performs better than genetic algorithm (GA) in optimizing sidelobe level of antenna array without any serious effect on the beamwidth. Since sidelobe level can be optimized through phase or amplitude excitations, it is found that randomly-amplitude excited elements of rectangular antenna array have good sidelobe level than randomly-phase excited elements of rectangular antenna array. The best sidelobe level obtained while using enhanced firefly was (32.5 dB) compared to the value of (20.0 dB) obtained with genetic algorithm. As a way of improving this or similar work, the author suggests that a comparison of enhanced firefly algorithm with all other key optimization methods or techniques should be undertaken.

It was also found that tilting beam towards the direction of end fire, genetic algorithm optimization technique can be used to reasonably reduce the level of sidelobe in array antennas. Equally worthy of note, as found from this work, is the fact that reducing the number of active elements in an antenna array by way of turning OFF some elements can be used to improve performance of the array.
