Compact Self-Octaplexing Circular EMSIW Antenna for Sub-6 GHz Communication Systems

A compact eighth mode circular substrate integrated waveguide (EMSIW) self-octaplexing antenna is proposed for sub-6 GHz communication systems in this paper. The designed antenna consists of coaxial fed eight EMSIW cavity resonators arranged in circular fashion. Each EMSIW cavity resonator utilizes the fundamental TM010 mode of the circular SIW cavity. The designed antenna operates at eight distinct frequencies of sub-6 GHz frequency spectrum. Isolations better than 23 dB is obtained among the different ports of the designed antenna. Moreover, each frequency band of designed antenna exhibits independent tunability without affecting the other frequency bands. Each resonator of the designed antenna can be tuned to any frequency between 3-5 GHz. The self-octaplexing antenna operates at 3.35, 3.58, 3.73, 3.91, 4.09, 4.32, 4.61 and 4.96 GHz with respective gains of 4.53, 4.62, 4.67, 4.74, 3.83, 3.89, 3.42, 3.55 dBi. The proposed antenna exhibits high inter-port isolation, good radiation characteristics and compact dimensions which makes it suitable candidate for sub-6 GHz communication systems.