A broadband planar rhombus monopole antenna for 28 GHz millimeter-wave communications

This paper presents a planar rhombus monopole antenna covering 24.408–34.533 GHz spectrum for fifth generation (5G) wireless mobile communications. The antenna structure is composed of rectangular rings and parasitic patches. The proposed antenna is built on 0.254 mm thin Rogers substrate and has dimensions of 7×7 mm
²
. It maintains an efficiency of more than 96% throughout its operational band with a peak gain of 5.6 dBi. The antenna is broadband having 36.16% bandwidth at 28 GHz. Linear and planar array configurations lead to very high gains of up to 14.2 dBi, beam-width as narrow as 8.4
^°
and very low side lobe level of −13.1 dB. The proposed antenna is an excellent choice for millimeter-wave and future (5G) mobile phone communications due to its simple design, easy fabrication and low cost.