Study and design of ultra-broadband loaded monopole antenna

This paper presents a ultra-broadband loaded monopole antenna. To broaden the operation bandwidth of the monopole antenna and efficiently resolve the problem of the nulls of the antenna pattern, a novel antenna design method is proposed by loading with lumped elements. The loads are parallel resistor/inductor (RL) circuits. The loaded antenna having a larger bandwidth, with the maximum gain is almost at the horizontal radiation direction. Finally the gain of the system is greater than -5 dBi over the entire frequency band of operation.