The effects of air-gap on spider radial line slot array (SRLSA) antenna for point to point application

The research presents the effects of an air gapped configuration on the compact radial line slot array antenna (RLSA). The proposed antenna is made feasible by using a coaxial feeding structure with the core is exactly before the FR4 substrate layer. This type of antenna has the ability to reduce surface wave excitation between elements which are separated by a ground plane. In this research, the varieties level of air gapped of proposed antenna is 7 mm, 8 mm and 9 mm in sequent. For high radiation efficiency antenna, it is convenient to choose the other lower permittivity of dielectric materials but it may contributes to more expensive cost since it involves with double substrates. The air-gapped antenna however has proven a better efficiency at 5.8 GHz. The optimum 7 mm gapped is capable of boosting a maximum gain up to 9.046 db with return loss of -23.5914 dB as well as 91.93% efficiency within the frequency range 5.5761 GHz to 6.2557 GHz. With all capabilities mentioned, the antenna is highly potential to be deployed for point to point application.