Circularly polarised MIMO ground radiation antennas for wearable devices

Abstract

Two ground radiation antennas with polarisation diversity performance were proposed for MIMO WLAN applications in wearable devices. The antennas can simultaneously excite the vertical mode and horizontal mode of the ground plane and the phase difference between the two modes can be controlled by utilising an inductor‐loaded metal strip in the ground plane, generating circular polarisation. A 3:1 VSWR bandwidth of 140 MHz with high isolation (above 17 dB) and a 3 dB axial ratio bandwidth of 100 MHz was obtained. The opposite rotations generated by the two antennas resulted in good diversity performance, which was verified by the measured envelope correlation coefficient.

A compact wide band textile MIMO antenna with very low mutual coupling for wearable applications

“…It is reported that the design could achieve about 15 dB of port isolation. In Reference , a wearable MIMO antenna for WLAN application is proposed. The antenna uses ground radiation with polarization diversity characteristics.…”

Dual‐band CPW fed MIMO antenna with polarization diversity and improved gain

“…A comparison of this work with published literatures is tabulated in Table in terms of number of bands, size, isolation, polarization and gain. The configuration in References are smaller in size than the proposed work. The proposed configuration has dual bands whereas the designs in References consist of a single band.…”

“…The configuration in References are smaller in size than the proposed work. The proposed configuration has dual bands whereas the designs in References consist of a single band. The triple‐band antenna with smaller size has poor isolation and LP.…”

“…The triple‐band antenna with smaller size has poor isolation and LP. The gain enhancement method is not introduced in References Compact dual‐band antennas are presented in References These have only LP and no gain enhancement techniques are described. In addition to this, via is used in References which increases design complexity.…”

“…Many researchers have proposed linearly polarized MIMO antenna with single‐band response in Reference and multiband responses in References and . Very few circularly polarized (CP) MIMO antennas are published in literatures . In Reference , MIMO antenna with polarization diversity is proposed; in this structure, a decoupling circuit is introduced to enhance the isolation.…”