Dual-band planar spiral monopole antenna for 28/38 GHz frequency bands

This paper presents a dual-band spiral planar monopole antenna working in 5G candidate bands of 28 and 38 GHz. Structure of the proposed antenna is a spiral that has two arms, each one responsible for a different resonant frequency. The antenna has a peak gain of 4.73 dBi and efficiency greater than 90% in both bands. The proposed antenna has a size of 4×8 mm
²
. A very high gain of 12.7 dBi is obtained when the antenna is used in an 8-element array configuration. The overall antenna array has a size of 8×48 mm
²
. The radiation patterns exhibit a very narrow beam-width of as narrow as 8 degrees. The high gain and small size makes this antenna suitable for future 5G mobile phones.