Four LTE low‐band smartphone antennas and their MIMO performance with user's hand presence

Abstract

ABSTRACTOwing to the narrow regions along the four edges of the modern smartphone, especially the two narrow regions along the long (side) edges thereof, it has been a design challenge to embed the internal antennas therein. The design challenge is especially critical for embedding the long‐term evolution (LTE) low‐band antennas with operating frequencies below 1 GHz. In this study, based on the open‐slot antenna structure, the design of four LTE low‐band antennas, respectively, disposed along the four edges of the smartphone are presented. The two antennas along the two short (top and bottom) edges have a low profile of 10 mm and can cover 698–960 MHz. The two antennas along the two long edges have a low profile of 1 mm only and can cover 824–960 MHz. The four antennas can be applied in a 4 × 4 multiple‐input multiple‐output (MIMO) system in the 824–960 MHz band (e.g., the LTE band 5 and 8). Conversely, the two short‐edge antennas can be used for 2 × 2 MIMO in the 698–960 MHz band (e.g., the LTE band 5, 8, 13, and 17). The operating principle and antenna performance of the four antennas are presented. The obtained channel capacities for 4 × 4 MIMO and 2 × 2 MIMO operations are also shown. Effects of the user's hand holding the smartphone with the four antennas therein are also analyzed. © 2016 Wiley Periodicals, Inc. Microwave Opt Technol Lett 58:2046–2052, 2016