A horizontally polarized omnidirectional slot antenna array

A horizontally polarized omnidirectional slot antenna array is proposed. The antenna comprises two slot-elements that cut onto the ground plane on a substrate, a feeding network, and two grounded side metallic plates. The antenna prototype is printed on an FR4 printed circuit board (PCB), with an overall size of 240 mm × 20 mm × 23 mm. It shows a desirable performance over the frequency range of 2.1-2.6 GHz, with return loss larger than 10-dB, maximum gain of 5.5 dBi, and omnidirectivity within ± 1.5 dB.