Wideband Filtering Antenna with Wide Suppression Band Based on Stacked Circular Patches

One wideband filtering antenna with wide rejection band based on circular patch is proposed in this paper. The filtering antenna consists of two circular patches, two short pins and a pair of half-mode slots. The stacked circular patch not only greatly improves the impedance bandwidth of the antenna, but also achieves a wide suppression band in the high stopband by using the high order modes of the circular patch. Without affecting the radiation mode, the antenna achieves a low stopband filtering effect by adding two pins and a pair of slots. The filtering antenna has the characteristics of wide bandwidth and wide out-of-band suppression. The measured results show that the operating frequency band of the filtering antenna is 2.05GHz-2.79GHz, and the maximum gain is 8.09dBi. The out-of-band suppression level in the lower stopband (1.2-1.8GHz) is more than 20dB, and the out-of-band suppression in the upper stopband (3.2-5.4GHz) is more than 15dB.