Proximity feed multiband patch antenna array with SRR and PBG for THz applications

In the present work, low profile proximity feed multiband patch antenna array have been investigated and presented. The proposed antenna is array of five similar split ring resonator (SRR) structures patch that are mounted on the upper layer of the liquid crystal polymer substrate and photonic band gape (PBG) structures are created in the underneath substrate to improve the performance of radiation characteristics. SRR characteristic has been matched with resonance frequencies of designed antenna and observed multi-band resonances below −14 dB at 0.58 THz, 0.61 THz, 0.64 THz, 0.67 THz, 0.74 THz, 0.77 THz, 0.800 THz, 0.84 THz, 0.86 THz and 0.89 THz. The proposed antenna is mounted on Liquid crystal polymer (LCP) substrate having dielectric constant of 2.9 and loss tangent of 0.00025. Out of ten multiband frequencies, we obtained peak gain, directivity and efficiency are 14.6 dB, 15.32 dBi and 85.4% respectively, at the corresponding resonance frequency of 0.74 THz with minimum return loss of −50.942. The achieved fractional bandwidth and performance of designed antenna are suitable for security, Video rate imaging, homeland, medical and material characterization application in the THz spectrum.