A multiresonant single-element wideband slot antenna

A technique for designing wideband slot antennas is proposed. By selecting the topology of the microstrip feed network, the aperture´s electric field distribution is manipulated to create two fictitious short circuits along the slot, hence creating two additional resonances besides the main one. The frequencies of these fictitious resonances can be chosen such that the overall bandwidth of the antenna is drastically increased. By using this technique, a slot antenna with a 1.8:1 bandwidth ratio is designed and fabricated. The measured results of this antenna show similar radiation patterns at different frequencies in its band of operation. Furthermore, the antenna has a relatively constant gain and, more importantly, it has an excellent polarization purity over the entire bandwidth.