A Low-Profile, Scalable 28-GHz Phased Array Antenna in Fan-Out Wafer-Level Package for 5G Communication

This paper presents a 4-element (2×2) dual-polarized 28-GHz phased array antenna in package (AiP) for 5G communication. The AiP utilizes advanced fan-out wafer-level package (FOWLP) technology embedding a 65-nm CMOS beamformer IC and yields a low profile of 0.47 mm. Despite such an extremely low profile, a practical bandwidth of 2 GHz (27–29 GHz) is achieved by slot-fed antenna design. The antenna element on the AiP exhibits an EIRP of 15.2 dBm with good uniformity due to high fabrication accuracy of FOWLP. The AiPs are designed to be scalable so that they can be arranged in two dimensions to make a larger-scaled array. A 16-elements (2×8) phased array module using the four AiPs exhibits a peak EIRP of 40.5 dBm and is capable of scanning within ±40° close to ideal beam patterns, indicating high scalability of the developed FOWLP-based AiP.