A wideband snowflake antenna for 28 GHz millimeter-wave communications is proposed. The antenna has a size of 8×5 mm 2 , fabricated on ultra-thin 0.254 mm substrate. The antenna consists of four small hexagons surrounding a bigger hexagon in order to attain broadband characteristics. Bandwidth response of the antenna is between 25.28-29.04 GHz (13.43% @ 28 GHz), having 3.12 dBi gain and more than 80% of radiation as well as total efficiency. The antenna specific structure is designed such that it gives dual beam over its entire bandwidth without a noticeable shift in its beam directions. For enhanced gain performance, its 4-element array (of size 32×12 mm 2) has been fabricated separately to increase its gain upto 10.12 dBi at 28 GHz. The proposed dual-beam antenna and its array has been modelled on thin Rogers substrate to show that its application in millimeter-wave communication equipment is viable. INDEX TERMS 5G, millimeter-wave, 28 GHz, broadband, dual-beam antennas, arrays, smartphones.

A wideband antenna with a high gain and narrow beam-width for future 5G communication systems is presented in this research. The antenna operates in 28 GHz 5G band with a large 35.53% bandwidth ranging from 23.41-33.92 GHz. The array has 4-elements arranged in a linear fashion to attain a high gain of 10.7 dBi. It radiates along its end-fire direction and provides a very narrow beam-width of 14.6 • in its H-plane. A corporate feed network specifically designed for thin substrates was used in order to excite the array elements. It is built upon thin 0.254 mm Rogers substrate to minimize transmission losses and attain high radiation efficiencies of more than 90% throughout its operating frequency range. It has a compact structure bearing low cost and is easy to fabricate. This antenna fulfills necessary requirements of 5G communication and is therefore a good candidate to be used in the millimeter-wave range. INDEX TERMS 5G, millimeter-wave, 28 GHz, wideband, future mobiles, antenna arrays.

A broadband antenna array for 28 GHz 5G communications is presented in this paper. The antenna array has dimensions of 45 × 20 mm2 and has a measured operating band in 25.052‐34.923 GHz frequency range. A 4‐way feed network to excite its array elements was designed and optimized for the operating band. The single element consists of two co‐centric wire hexagons backed by another hexagonal ground loop of larger radius. The resulting monopole is surrounded by vias arranged in an inverted U‐shape manner for better performance. The antenna array has a minimum radiation efficiency of 85% with peak gain of 12.15 dBi. The antenna has narrow beam‐widths of 44.3° and 12.5° in two of its respective planes. The antenna is fabricated on an ultra‐thin Rogers substrate. The proposed antenna is deemed suitable for future 5G communication systems due to its simple design, compact size and low fabrication cost.

This study presents a 5G antenna array for millimetre‐wave communications. Overall size of the proposed antenna array is 40 × 15 mm2, and operates in a measured 23.76–42.15 GHz frequency range. A planar four‐way feed network has been designed, optimised and used to excite the antenna array elements. The single element of the array is spiral monopole surrounded by a boundary of vias with extended ground plane in an inverted U‐shaped manner. Hexagonal parasitic patches have been introduced at the backside to enhance impedance performance of the antenna element. Peak gain of the proposed antenna array is 11.5 dBi with radiation efficiency more than 83% in its entire operating band. The antenna gives a narrow beam‐width of as low as 10.1°. Single element and its 1 × 4 array have been fabricated using standard printed circuit board (PCB) process. Measured results show excellent compliance with the simulated design objectives. The antenna is low cost, low profile with simple design and is capable of being deployed in future 5G communication mobile networks.

This article presents a simple antenna array for millimeter‐wave communications at 28 GHz. The proposed antenna array is 40 × 19.22 mm2 in size and operates in a measured 26.04 to 30.63 GHz frequency range. The antenna array elements are excited by a planar four‐way feed network, which has been designed and optimized for optimum performance. The single element of the proposed antenna array is a rhombic monopole surrounded by a series of vias, square parasitic patches were etched on the back side to enhance its impedance performance. The proposed antenna array has a peak gain of 11.24 dBi with radiation efficiency more than 85% in its entire operating band. Both single and its 4 × 1 array have been modeled, simulated, and fabricated using standard PCB process. Excellent agreement exists between the simulated and measured results. The antenna's simple design, compact size, and low fabrication cost, enables it to be deployed in millimeter‐wave communication systems.