Multimode Balanced Mu-Near-Zero Loop Antenna for Wi-Fi 6/6E Applications in Full Metal Housing Tablet Computers

In this article, we introduce a balanced broadband mu-near-zero (MNZ) loop antenna, which is designed for Wi-Fi 6/6E applications in full metal housing tablet computers. Different from the previous MNZ segmented loop antenna with the single
$0^{\text {th}}$
mode, the higher order
$1^{\text {st}}$
/
$2^{\text {nd}}$
/
$3^{\text {rd}}$
modes are also included for broadband purpose. By adjusting the effective permeability through the distributed capacitors in the proposed antenna, the electrical lengths of the
$0^{\text {th}}$
/
$1^{\text {st}}$
/
$2^{\text {nd}}$
/
$3^{\text {rd}}$
modes are reasonably stretched. This allows for multimode synergy in a single MNZ loop located in full metal housing computers. Therefore, the proposed MNZ loop antenna, with a planar structure of
$6.8\times 45.4$
mm2, exhibits a broad bandwidth with
$S_{11} \lt -6$
dB from 4.5 to 7.5 GHz, covering Wi-Fi 6/6E bands. As another merit for practical applications, this broadband MNZ loop antenna is also balanced with less current on the motherboard, performing excellent robustness against changes in tablet computer sizes or affecting by hands. The proposed MNZ loop antenna, with its multiple modes, offers valuable insights for the development of broadband and robust antennas in full metal housing devices.