A high-gain dual-polarised planar etched slot array for use in wireless
local area networks (WLAN) is presented. Two sets of four collinear
slots are used as radiators for each polarisation. Each set of four collinear slots is constructed as a centre-fed long slotline, with etched
crossovers to split the slotline into four resonant and in-phase halfwavelength slots. A reflector etched on a separate substrate spaced a quarter-wavelength away from the slot array ensures unidirectional radiation. The final antenna achieved a gain of 14.5 dBi, a return loss better than 10 dB, and port isolation in excess of 30 dB over the 2.4–2.484 GHz WLAN frequency band.