Various antenna architectures, offering frequency band-notched function, have been proposed [1] [2] [3]. In these antennas, band-notched function is achieved by adding a stepped impedance resonator (SIR) or a split ring resonator (SRR) on the feed line, or cutting slots in the ground plane. In [4], a wideband planar antenna that suppresses the interferences from system operating from 5GHz to 6 GHz has been reported, where the interferences suppression function is achieved by adjustment of the length of the extended strip. These antennas are attractive for wireless communications, being especially effective for interferences suppression because of their simple structures. However, the above antennas have limited frequency band suppression performance: 1. the investigation of an array antenna with 2nd harmonic suppression function has not been discussed; 2. the gain suppression is less than 10dB