Sidelobe Radiation Suppression of Wideband Horn Antennas by Utilizing SRR Arrays

A sidelobe reduction strategy that employs split ring resonator (SRR) arrays is introduced for wideband horn antennas. The developed SRR array comprises five SRRs that placed side by side at equal intervals. By incorporating the developed SRR arrays with the pyramidal horn antenna, the E-plane sidelobe radiation levels of the antenna are reduced significantly without disturbing the mainlobes of the H-plane radiation patterns and meanwhile the realized gain of the horn antenna is enhanced by more than 1.36 dB over the operational band of 8-9 GHz. Moreover, the loading of the SRR arrays does not deteriorate the radiation efficiency and impedance matching of the horn antenna.