Design of 2×2 array antenna with harmonic suppression using T-shape DGS and spurline

In this paper, a new design of 2×2 array antenna with harmonic suppression using defected ground structure (DGS) and spurline has been developed to suppress the undesired signals at harmonic frequency. The results achieve a very good return loss which peaked up to −33.44 dB at 2.45 GHz operating frequency which makes it great promising applications for RF/Microwave energy transfer particularly in suppressing the harmonic that degrade the system performance. The antenna has an extremely high gain which achieved a 14.20 dB with a strong directional radiation pattern; and total efficiency achievement of the 2×2 antenna array is up to 98.86%. Besides that, the excitation of harmonic signals have been suppressed effectively from −29.19 dB to −7.77 dB at frequency of 3.24 GHz and achieved a wider stopband up to 8 GHz. Experimentally, the measured and simulated results are found in an excellent agreement.