A Novel Half Mode SICL Based Dual Beam Antenna Array for Ka-Band Application

Abstract

In this paper, we propose a novel Half Mode Substrate Integrated Coaxial Line (HMSICL) cavity fed monopole antenna at 28 GHz. A SICL cavity is bisected along its symmetric magnetic wall (PMC) to create an open-ended Half Mode SICL (HMSICL) cavity. The proposed HMSICL cavity is used to excite a tapered monopole antenna to radiate in endfire direction with a gain of 6.4 dBi at 28 GHz. For dual beam application, it is integrated with unidirectional broadside Half Mode Substrate Integrated Waveguide (HMSIW) antenna exhibiting a gain of 5.1 dBi that provides spatial diversity to the proposed design. To achieve high gain, two co-located 1 × 4 linear HMSICL and HMSIW array are placed sideby-side such that the proposed design produces simultaneous endfire and broadside beams for In-Band Full Duplex (IBFD) applications. The proposed passive Signal Interference Cancellation (SIC) technique is utilized to minimize the overlap of simultaneous dual beam at 28 GHz by orienting the two antennas within a compact footprint. The full duplex antenna array achieves a gain of 10.8 dBi in endfire and 10.3 dBi in broadside direction with high isolation below 45 dB over 500 MHz bandwidth. The presented antenna array is a potential candidate for relay where the transmitting and receiving signals are in two different directions. INDEX TERMS Half mode SICL (HMSICL), half mode SIW (HMSIW), high isolation.The associate editor coordinating the review of this manuscript and approving it for publication was Sotirios Goudos .transmission and reception through a relay at base stations. Communication in urban cities is possible through an efficient multi-hop link between Non-Line-of-Sight (NLOS) end-users. Relays with simultaneous dual beam establish a communication link between two end users for NLOS communication [1] as shown in Fig. 1. An In-Band Full Duplex (IBFD) antenna array used in streetlight deployment and over building is the upcoming easy cost-effective solution for deployment in Ka-band for faster Vehicle-to-Vehicle communication. However, IBFD antennas have been regarded impractical in the past due to the strong Self Interference (SI). Several active and passive suppression techniques such as passive suppression through antenna isolation, active suppression via analog and digital cancellation [2] have been proposed to compensate for self interference. The basic passive suppression technique is the physical separation of the