Millimeter-Wave Air-Filled SIW Antipodal Linearly Tapered Slot Antenna

The emerging millimeter-wave wireless technologies spur the development of low-cost and high-performance devices, circuits, and systems. It is in this context that an air-filled substrate integrated waveguide (AFSIW) antipodal linearly tapered slot antenna (ALTSA) made of a multilayer printed circuit board process is proposed in this letter. The proposed three-layered AFSIW structure provides very low loss and is of high interest for the design of highly efficient ALTSA. For comparaison, the proposed AFSIW ALTSA and a convientional SIW ALTSA are designed, fabricated, and measured at Ka-band (26-40 GHz). For identical dimensions, at 35.5 GHz, the proposed antenna exhibits a 17° narrower measured xy-plane half-power beamwidth and a simulated radiation efficiency improved by 2.9%. The narrower beamwidth and efficiency improvement results in a simulated directivity and measured gain improved by 3.9 and 4 dB, respectively, at the same frequency. This antenna is of interest for the design of efficient array based on AFSIW feeding network.