Ali Shahid M, Sovuthy Cheab, Noghanian Sima, Ali Zulfiqur, Abbasi Qammer H, Imran Muhammad A, Saeidi Tale, Socheatra Soeung
Department of Electrical and Electronic Engineering, Universiti Teknologi, PETRONAS Bander Seri Iskandar, Tronoh 32610, Perak, Malaysia.
Wafer LLC, 2 Dunham Rd, Beverly, MA 01915, USA.
Micromachines (Basel). 2021 Apr 22;12(5):475. doi: 10.3390/mi12050475.
The human body is an extremely challenging environment for wearable antennas due to the complex antenna-body coupling effects. In this article, a compact flexible dual-band planar meander line monopole antenna (MMA) with a truncated ground plane made of multiple layers of standard off-the-shelf materials is evaluated to validate its performance when worn by different subjects to help the designers who are shaping future complex on-/off-body wireless devices. The antenna was fabricated, and the measured results agreed well with those from the simulations. As a reference, in free-space, the antenna provided omnidirectional radiation patterns (ORP), with a wide impedance bandwidth of 1282.4 (450.5) MHz with a maximum gain of 3.03 dBi (4.85 dBi) in the lower (upper) bands. The impedance bandwidth could reach up to 688.9 MHz (500.9 MHz) and 1261.7 MHz (524.2 MHz) with the gain of 3.80 dBi (4.67 dBi) and 3.00 dBi (4.55 dBi), respectively, on the human chest and arm. The stability in results shows that this flexible antenna is sufficiently robust against the variations introduced by the human body. A maximum measured shift of 0.5 and 100 MHz in the wide impedance matching and resonance frequency was observed in both bands, respectively, while an optimal gap between the antenna and human body was maintained. This stability of the working frequency provides robustness against various conditions including bending, movement, and relatively large fabrication tolerances.
由于复杂的天线-人体耦合效应，人体对于可穿戴天线来说是一个极具挑战性的环境。在本文中，对一种由多层标准现货材料制成的带有截断接地平面的紧凑型柔性双频平面曲折线单极天线（MMA）进行了评估，以验证其在不同受试者佩戴时的性能，从而帮助设计未来复杂的体内/体外无线设备。该天线已制作完成，测量结果与模拟结果吻合良好。作为参考，在自由空间中，该天线提供全向辐射方向图（ORP），在较低（较高）频段具有1282.4（450.5）MHz的宽阻抗带宽，最大增益为3.03 dBi（4.85 dBi）。在人体胸部和手臂上，阻抗带宽分别可达688.9 MHz（500.9 MHz）和1261.7 MHz（524.2 MHz），增益分别为3.80 dBi（4.67 dBi）和3.00 dBi（4.55 dBi）。结果的稳定性表明，这种柔性天线对人体引入的变化具有足够的鲁棒性。在两个频段中，分别观察到宽阻抗匹配和谐振频率的最大测量偏移为0.5 MHz和100 MHz，同时天线与人体之间保持了最佳间隙。工作频率的这种稳定性为包括弯曲、移动和相对较大的制造公差在内的各种条件提供了鲁棒性。
