Barik Rusan Kumar, Koziel Slawomir
School of Microelectronics, Southern University of Science and Technology, Shenzhen, China.
Engineering Optimization and Modeling Center, Reykjavik University, Reykjavik, 102, Iceland.
Sci Rep. 2024 Nov 13;14(1):27767. doi: 10.1038/s41598-024-79609-3.
This communication presents an ultra-miniaturized two-way frequency tunable antenna diplexer based on cavity-backed slots and dielectric fluids. The proposed antenna utilizes two half-mode substrate-integrated rectangular cavities loaded with slots and fluidic pockets. The conventional size reduction is achieved by employing half-mode cavities, whereas ultra-miniaturization is obtained by applying the slots, which provides additional capacitive loading. As the cavities are of unequal sizes, a weak cross-coupling path is created between the ports to obtain high isolation (> 30 dB). The isolation is further enhanced by loading the slots. Two mechanisms are analyzed to tune the frequency bands individually or simultaneously. Firstly, the width of the slots can be altered to tune the frequency bands. However, this method involves modification of the physical dimensions of the antenna. Secondly, fluidic vias are created on the bottom plane of the cavities. These can be filled with various dielectric liquids to achieve frequency reconfigurability without altering the physical dimensions of the antenna. To demonstrate the concepts considered, the prototype of the proposed antenna was fabricated and experimentally validated. The structure has a footprint of 0.045λ and an isolation exceeding 33.4 dB. The operating frequencies are tunable in the range from 3.08 to 3.84 GHz (lower band) and from 4.97 to 6.33 GHz (upper band) by varying the dimensions of the slots whereas the operating frequencies are reconfigurable in the range from 2.74 to 3.38 GHz (lower band) and from 4.54 to 5.58 GHz (upper band), by employing microfluidic approach. As a result, the working frequencies may be varied in the range from 2.74 to 3.84 GHz (lower band) and from 4.54 to 6.33 GHz (upper band), making this antenna diplexer a competitive candidate for several communication systems. The cross-polarization levels, front-to-back ratio, and realized gain are greater than 19 dB, 18 dB, and 2. dBi, respectively. Excellent consistency is observed between full-wave simulation results and the measurement data.
本文介绍了一种基于背腔缝隙和介电流体的超小型双向频率可调天线双工器。所提出的天线利用了两个加载有缝隙和流体腔的半模基片集成矩形腔。传统的尺寸缩减通过采用半模腔来实现，而超小型化则通过应用缝隙来实现，缝隙提供了额外的容性负载。由于腔体尺寸不相等，在端口之间创建了一条弱交叉耦合路径以获得高隔离度（> 30 dB）。通过加载缝隙进一步提高了隔离度。分析了两种机制来单独或同时调谐频段。首先，可以改变缝隙的宽度来调谐频段。然而，这种方法涉及天线物理尺寸的修改。其次，在腔体的底面创建流体过孔。这些过孔可以填充各种介电液体，以在不改变天线物理尺寸的情况下实现频率可重构性。为了验证所考虑的概念，制作了所提出天线的原型并进行了实验验证。该结构的占地面积为0.045λ，隔离度超过33.4 dB。通过改变缝隙的尺寸，工作频率可在3.08至3.84 GHz（低频段）和4.97至6.33 GHz（高频段）范围内调谐，而通过采用微流体方法，工作频率可在2.74至3.38 GHz（低频段）和4.54至5.58 GHz（高频段）范围内重构。结果，工作频率可以在2.74至3.84 GHz（低频段）和4.54至6.33 GHz（高频段）范围内变化，使得这种天线双工器成为几种通信系统的有竞争力的候选者。交叉极化水平、前后比和实现增益分别大于19 dB、18 dB和2 dBi。全波仿真结果与测量数据之间观察到极好的一致性。
