Faculty of Engineering, Rajamangala University of Technology Rattanakosin, Nakhon Pathom 73170, Thailand.
School of Engineering, King Mongkut's Institute of Technology Ladkrabang, Bangkok 10520, Thailand.
Sensors (Basel). 2022 Jul 17;22(14):5338. doi: 10.3390/s22145338.
This research proposed a portable wideband horizontally-polarized directional antenna scheme with a radome for digital terrestrial television reception. The operating frequency band of the proposed antenna scheme is 470-890 MHz. The portable antenna scheme was an adaptation of the Yagi-Uda antenna, consisting of a folded bowtie radiator, a semicircular corrugated reflector, and a V-shaped director. Simulations were carried out, and an antenna prototype was fabricated. To validate, experiments were undertaken to assess the antenna performance, including the impedance bandwidth (|| ≤ -10 dB), gain, and unidirectionality. The measured impedance bandwidth was 75.93%, covering 424-943 MHz, with a measured antenna gain of 2.69-4.84 dBi. The radiation pattern was of unidirectionality for the entire operating frequency band. The measured xz- and yz-plane half-power beamwidths were 150°, 159°, 160° and 102°, 78°, 102° at 470, 680, and 890 MHz, with the corresponding cross-polarization below -20 dB and -40 dB. The radome had a negligible impact on the impedance bandwidth, gain, and radiation pattern. The power obtained for the outdoor test, at 514 MHz, was 38.4 dBµV (-70.4 dBm) with a carrier-to-noise ratio (C/N) of 11.6 dB. In addition, the power obtained for the indoor test was 26.6 dBµV (-82.2 dBm) with a C/N of 10.9 dB. The novelty of this research lies in the concurrent use of the Yagi-Uda and bowtie antenna technologies to improve the impedance bandwidth and directionality of the antenna for digital terrestrial television reception.
本研究提出了一种具有天线罩的用于数字地面电视接收的便携式宽带水平极化定向天线方案。所提出的天线方案的工作频段为 470-890 MHz。便携式天线方案是对八木天线的改进，由折叠蝶形辐射器、半圆形波纹反射器和 V 形引向器组成。进行了仿真，并制作了天线原型。为了验证，进行了评估天线性能的实验，包括阻抗带宽（|| ≤ -10 dB）、增益和单向性。测量的阻抗带宽为 75.93%，覆盖 424-943 MHz，测量的天线增益为 2.69-4.84 dBi。辐射方向图在整个工作频段具有单向性。在 470、680 和 890 MHz 时，xz 和 yz 平面的半功率波束宽度分别为 150°、159°、160°和 102°、78°、102°，相应的交叉极化低于-20 dB 和-40 dB。天线罩对阻抗带宽、增益和辐射方向图的影响可以忽略不计。在 514 MHz 时，室外测试获得的功率为 38.4 dBµV（-70.4 dBm），载噪比（C/N）为 11.6 dB。此外，室内测试获得的功率为 26.6 dBµV（-82.2 dBm），载噪比为 10.9 dB。本研究的新颖之处在于同时使用了八木天线和蝶形天线技术，以提高天线的阻抗带宽和方向性，用于数字地面电视接收。
