60-GHz Compact Multidirectional, Multibeam Antenna-in-Package

Abstract

In this study, a multidirectional, multibeam antenna-in-package (AiP) was proposed for the 60-GHz unlicensed band (57–66 GHz). The vertically polarized end-fire horn antenna and broadside horn antennas were arranged and integrated in a single substrate with a 1 × 4 array structure to cover all the radial axes. In contrast to previous horn-type AiP structures, a guard via was added to suppress back radiation. In addition, impedance matching vias and impedance matching patches were analyzed in detail to widen the impedance bandwidth. The guard via was also analyzed. An efficient AiP was designed by minimizing the overlapped beamwidth of the antenna radiating in broadside and end-fire directions; this was possible because the E- and H-plane beamwidths, respectively, can be adjusted by controlling the horn aperture. Each beamforming function of the broadside and end-fire array was realized by integrating each radio frequency integrated circuit to the corresponding array. The size of the antenna was 7.5 mm × 10.6 mm × 1.51 mm (=1.5 × 2.12 × 0.302 λ