2 X 2 etched slot array with corporate slotline feed network

Measured and simulated results for a planar 2times2 slot array corporately fed by a slotline feed network are presented. The antenna array has a coplanar-waveguide input port and the slots are etched on the finite ground plane of a single substrate. The coplanar-waveguide transmission line is transitioned into a four-way slotline feed network, which directly feeds the four half-wavelength slots from the narrow edges of the slots. An experimental array achieved an impedance bandwidth of more than 12%, stable bidirectional radiation patterns with low cross-polarisation, and a maximum gain of more than 8 dBi.