Design of a Dual-Branch Dual-band Monopole Based MIMO Antenna for 5G mm-wave Smartphone Applications

An eight element dual-band MIMO antenna operating at n257 and n260 band frequencies for 5G operation in smart phones is delineated in this article. To reserve an apposite space for the other antennas, the elements are positioned symmetrically alongside the longer edges of the smartphone, with 4 antenna elements on each side. The individual antenna element is a dual-branch monopole with a vertical orientation and is fed by a
$50\Omega$
micro-strip line. With the center frequencies at 28 GHz, and 38 GHz a −10 dB impedance matching bandwidth of 2.5 GHz and 3 GHz are observed, respectively. A maximum gain of 8 dBi is observed at the lower band resonant mode frequency and a maximum gain of 5 dBi is observed at the upper band resonant mode frequency for the single antenna element.