Wideband planar plate monopole antenna with dual tunable notch

A tunable dual notch planar plate monopole antenna operating over 3-16 GHz bandwidth is introduced. To create the notch, a modified U-slot is placed on the monopole plate. Owing to the narrow width of the modified U-slot several slots can be placed on top of each other to create multiple notch-bands over the antenna operating bandwidth. The results for an antenna with two modified U-slots are presented. By placing a small capacitor on each of the slots in a suitable position, it is shown that the centre frequency of each notch can be individually shifted downwards by up to 2 GHz, without changing the notch-bandwidths. Simulated as well as measured results are presented and compared.