Dual-Polarized Highly Folded Bowtie Antenna with Slotted Self-Grounded Structure for Sub-6 GHz 5G Applications

In this paper, a novel dual-polarized highly-folded self-grounded Bowtie antenna that is excited through I-shaped slots is proposed for applications in sub-6GHz 5G multiple-input-multiple-output (MIMO) antenna systems. The antenna consists of two pairs of folded radiation petals whose base is embedded in a double layer of FR-4 substrate with a common ground-plane which is sandwiched between the two substrate layers. The ground-plane is defected with two I-shaped slots located under the radiation elements. Each pair of radiation elements are excited through a microstrip line on the top layer with RF signal that is 180° out of phase with respect to each other. The RF signal is coupled to the pair of feedlines on the top layer through the I-shaped slots from the two microstrip feedlines on the underside of the second substrate. The proposed feed mechanism gets rid of the otherwise bulky balun. The Bowtie antenna is a compact solution with dimensions of 32×32×33.8 mm3. Measured results have verified that the antenna operates over a frequency range of 3.1–5 GHz and exhibits an average gain and antenna efficiency in the vertical and horizontal polarizations of 7.5 dBi and 82.6%, respectively

Recent Advances in the mm-Wave Array for Mobile Phones

With the development of communication system to the mm-wave band, the antenna design in the mm-wave band for mobile phones encounters new requirements and challenges. The mm-wave characteristics of short wavelength, high free-space path loss, and easy-to-be-blocking usually require mm-wave antennas with high gain and beam-scanning capability. Also, considering the very limited space occupied by antennas in mobile phones and the massive production of consumer electronics, small size, low cost, multiband, multi-polarization, and wide beam steering becomes the main key point of mm-wave array performance. In addition, as a special situation of the mobile antenna, the analysis of effect of the human tissue on the antenna performance is also important. So, in this chapter, a comprehensive summary on the recent advances in the mm-wave array for mobile phones including single-band, dual-band, and reconfigurable design of broadside array, horizontal polarized, vertical polarized, and dual-polarized design of endfire array, co-design of mm-wave array with lower band antenna, and user influence are summarized