This paper presents the optimization of bandwidth, gain and beamwidth of an 8-patch serial antenna 8-PSA based on the bat algorithm. This technique is in charge of finding the geometrical variables needed for antenna design, in order to find the best combination of values for a targeted antenna metric. It aims to obtain different antenna parameters for specific requirements of a highly directive antenna. A 750 MHz operating band is desired to comply with a typical 5G frequency segment. A maximum realized gain at θ=90° of 16 dB and a beamwidth as close as possible to 10° are targeted in the algorithm. The optimized antenna exceeds the requirements since the algorithm is able to obtain a bandwidth of 1 GHz, a maximum realized gain of 16.9 dB and half power beamwidth of 72° and 8.9° at both planes. The overall structure has a size of 21.6x21.6cm2. The bat algorithm only needs 10 iterations to achieve targeted requirements for antenna parameters.