Phased Array Antenna-in-Package Design for True-Wideband mmWave 5G Communication

The phased array design for millimeter (mmwave) 5G communication need numerous concurrent features, such as wide bandwidth, high gain, dual-polarization, and wide beam scanning capability. However, due to mutual coupling and grating lobe issues, it is difficult to simultaneously attain a real wideband operation for all of the aforementioned parameters. Most published papers have only demonstrated wideband operation for one or two parameters. To achieve a true wideband performance, this work used a variety of design techniques, including stacked patch architecture, electromagnetic band gap (EBG) structures, and the rotation of components. In this paper, a 5 by 5 phased array is realized in a multilayered low-temperature co-firing ceramic (LTCC) substrate, along with its feeding network. The phased array's element is designed to be a dual linear polarized stacking patch antenna with notched corners to ensure the antenna's wide bandwidth. The orientation of the array element is adjusted 45 degrees for mutual coupling reduction. The proposed phased array achieved a bandwidth of 6 GHz (24 to 30 GHz). It also achieves a maximum gain of 17.5 dB and a beam steering capability from -50 to +50 degrees. The features of multilayered implementation, low dielectric loss, and excellent packaging properties ensure a compact and high-efficiency phased array design and qualify this design as an antenna-in-packaging (AiP) design.