Dual null steering and limited beam peak steering using a triple mode microstrip patch antenna

A triple mode microstrip patch antenna has been studied for more than one null steering and limited beam peak steering purposes. The antenna consists of circular microstrip patch, and two concentrating annular rings around it. The circular patch supports TM11 mode while the rings operates in TM21 and TM31 modes, respectively. By controlling the radiating mode's amplitude and phase ratios, far field radiation pattern of this antenna can be reconfigured. Simulation studies show that the radiation pattern has two nulls which can be steered independently and is highly desired feature for an antijamming antenna. Full hemispherical null steering along with limited beam peak steering has been observed.