Harmonic suppression slot antenna using rectangular defected ground structure

In this letter, a wide rectangle-shaped microstrip-fed 2.62 GHz slot antenna using defected ground structure (DGS) with a low design complexity is proposed to achieve wideband harmonic suppression. To accomplish this, two rectangular DGS (RDGS) with various positions and dimensions are etched into the ground plane, which could have a wide band-stop characteristic. Simulated and measured return losses indicate that proposed structure effectively suppress the third harmonic up to 23 dB between 3 and 10.5 GHz with a maximum ripple of 2 dB. In addition, the measured radiation pattern and peak gain of the antenna show at least 17 dB and 7.1 dBi, respectively suppression at the third harmonic frequency of 7.86 GHz.