Research on a Novel Folded Monopole With Ultrawideband Bandwidth

In this letter, a novel folded monopole antenna with an ultrawideband (UWB) bandwidth and omnidirectional radiation performance has been proposed. An inverted “S”-type structure was formed by folding the planar monopole, which not only realizes dimension reduction, but also contributes to a decrease in the size of the ground plane; the proposed monopole antenna, meanwhile, has a more circular radiation pattern with the frequency ratio of 3.4:1, compared to the planar monopole antenna. Simulation has been carried out together with the measurement of the fabricated antenna. Good agreement between the measured and simulated results can be observed, showing that the antenna is capable of working in the frequency range from 3.1 to 10.6 GHz with return loss less than -10 dB.