Design of New Circularly Polarized Wearable Dielectric Resonator Antenna for Off-Body Communication in WBAN Applications

Abstract

A unique circularly polarized (CP) compact wearable dielectric resonator antenna (DRA) has been proposed for off-body communication in wireless body area network (WBAN) applications. The design is singly fed and a new H-shaped conformal metal strip has been used to excite the DRA. A circular polarization over a bandwidth of ∼9.6% (7.47-8.25 GHz) in conjunction with an impedance matching bandwidth of ∼20.7% (6.95-8.68 GHz) has been offered by the antenna. A prototype has been fabricated and measured. The antenna has been tested both in free space and on-body environment. A robust performance has been offered by the antenna against human body lossy effects. The measured results agree very well with the simulated results.INDEX TERMS Wireless body area network, ultra-wideband, dielectric resonator antenna, circular polarization, off-body communication, specific absorption rate.

A low‐profile circularly polarized dielectric patch antenna with bandwidth expansion

“…Although the CP DP antenna in Reference 25 has a wider AR bandwidth, the low‐profile characteristic cannot be kept. On the other hand, benefiting from the adoption of the DP antenna, it can be observed that the proposed antenna owns a lower profile and a higher gain than all CP DR antennas in References 12‐17 The gain of CP DR antenna in Reference 16 is higher than that of the proposed antenna, partly because a relatively large reflector is used.…”

“…To achieve higher data rate and larger information capacity, many approaches have been reported to expand the 3 dB axial ratio (AR) bandwidth of the CP DR antenna, 12‐19 which can be mainly classified into two categories. In the first approach, the multiple modes are merged together by employing special‐shaped DR such as hollow cylindrical, 12 spidron fractal, 13 high‐aspect ratio, 14 stair‐shaped, 15 and two‐layer nested 16 .…”

“…In the first approach, the multiple modes are merged together by employing special‐shaped DR such as hollow cylindrical, 12 spidron fractal, 13 high‐aspect ratio, 14 stair‐shaped, 15 and two‐layer nested 16 . In the second approach, various hybrid feeding structures are adopted, such as H‐shaped conformal metal strip, 17 dual pair of right‐angled microstrip line, 18 and truncated rectangular patch, 19 to improve coupling or introduce additional resonant modes (generated by the feeding structure). However, the above antennas radiate through the top wall and sidewalls of the DR, which results in a relatively low gain.…”

A chronological review of circularly polarized dielectric resonator antenna: Design and developments

“…This section highlights the state‐of‐the‐art developments of CPDRA using single point feed 11‐64 and multi‐point feed power divider, 65‐76 along with modification of three dimensional DR shapes 77‐103 . In this review article, the authors have segregated CP mechanism in terms of excitation of feeding techniques like microstrip line, coaxial probe, and aperture coupled feed, which will be helpful to the researcher to get the complete idea about the developments of particular excitation feeding method …”

“…One of the fundamental subjects in the broad area of DRA is the excitation scheme, which deals with the problem of how to couple the electromagnetic energy from the feeding transmission line to the dielectric radiator efficiently. Feeding techniques can be divided into single point feed and multi‐point feed power divider, which plays an important role in generation of CP for the case of DRA over three and half decades 11 ‐76 …”