Filtering antenna

In this letter, a compact pattern reconfigurable filtering microstrip antenna is presented with broad bandwidth, good selectivity at the passband edge, and flat gain frequency response. The pattern reconfigurable filtering antenna has four resonant modes which can be adjusted independently, three of them are created by multi-mode resonator (MMR) and the other one is by radiator. The four resonant modes are well distributed in desired band and the resonant mode of radiator is located between the first two resonant modes of MMR.