Edinburgh Napier University

  This paper presents the results of a study on developing an effective technique to increase the performance characteristics of array antennas for sub-THz integrated circuit applications. This is an essential to compensate the limited power of sub-THz sources. Although conventional array structures can provide a solution to enhance the radiation-gain however in the case of small-sized array structures the radiation properties can be adversely affect due to mutual coupling between the radiating elements. It is demonstrated here the effectiveness of using SIW technology to suppress surface wave propagations and near field mutual coupling. Prototype 2×3 antenna array with dimensions 20×13.5×0.125 mm 3 were designed and constructed on a dielectric substrate with thickness of 125 m for operation across 0.19-0.20 THz. The metallization of the antenna was coated with 500 nm layer of Graphene. With the proposed technique the isolation between the radiating elements was improved on average by 22.5 dB compared to a reference array antenna with no SIW isolation. The performance of the array was enhanced by transforming the patch to exhibit metamaterial characteristics. This was achieved by embedding an array of periodic slots of sub-wavelength in the patch. Compared to the reference array the metamaterial inspired structure exhibits an isolation, radiation gain and efficiency improvement on average by 28.5dB, 6.7dBi, and 36%, respectively. These results show the viability of proposed approach in developing array antennas for application in sub-THz integrated circuits. Keywords: Sub-terahertz (THz) frequency, substrate integrated waveguide (SIW), metamaterial (MTM), high isolation, high gain, graphene-layer, antennas arrays.