Milijic Marija, Jokanovic Branka, Tasic Miodrag, Jovanovic Sinisa, Boric-Lubecke Olga, Lubecke Victor
The Faculty of Electronic Engineering, University of Nis, 18000 Nis, Serbia.
The Institute of Physics, University of Belgrade, 11000 Belgrade, Serbia.
Sensors (Basel). 2025 Aug 12;25(16):4980. doi: 10.3390/s25164980.
This paper presents the novel design of a printed, low-cost, dual-port, and dual-polarized slot antenna for microwave biomedical radars. The butterfly shape of the radiating element, with orthogonally positioned arms, enables simultaneous radiation of both vertically and horizontally polarized waves. The antenna is intended for full-duplex in-band applications using two mutually isolated antenna ports, with the CPW port on the same side of the substrate as the slot antenna and the microstrip port positioned orthogonally on the other side of the substrate. Those two ports can be used as transmit and receive ports in a radar transceiver, with a port isolation of 25 dB. Thanks to the bow-tie shape of the slots and an additional coupling region between the butterfly arms, there is more flexibility in simultaneous optimization of the resonant frequency and input impedance at both ports, avoiding the need for a complicated matching network that introduces the attenuation and increases antenna dimensions. The advantage of this design is demonstrated through the modeling of an eight-element dual-port linear array with an extremely simple feed network for high-gain biosensing applications. To validate the simulation results, prototypes of the proposed antenna were fabricated and tested. The measured operating band of the antennas spans from 2.35 GHz to 2.55 GHz, with reflection coefficients of less than-10 dB, a maximum gain of 8.5 dBi, and a front-to-back gain ratio that is greater than 15 dB, which is comparable with other published single dual-port slot antennas. This is the simplest proposed dual-port, dual-polarization antenna that enables straightforward scaling to other frequency bands.
本文介绍了一种用于微波生物医学雷达的印刷式、低成本、双端口和双极化缝隙天线的新颖设计。辐射元件呈蝶形，其臂相互正交定位，能够同时辐射垂直极化波和水平极化波。该天线旨在用于使用两个相互隔离的天线端口的全双工带内应用，共面波导端口与缝隙天线位于基板的同一侧，微带端口正交位于基板的另一侧。这两个端口可在雷达收发器中用作发射和接收端口，端口隔离度为25 dB。由于缝隙呈蝴蝶结形状以及蝶形臂之间有一个额外的耦合区域，在同时优化两个端口的谐振频率和输入阻抗方面具有更大的灵活性，无需复杂的匹配网络，该网络会引入衰减并增加天线尺寸。通过对具有极其简单馈电网络的八元双端口线性阵列进行建模，证明了该设计在高增益生物传感应用中的优势。为了验证仿真结果，制作并测试了所提出天线的原型。天线的实测工作频段为2.35 GHz至2.55 GHz，反射系数小于 -10 dB，最大增益为8.5 dBi，前后增益比大于15 dB，与其他已发表的单双端口缝隙天线相当。这是所提出的最简单的双端口、双极化天线，能够直接扩展到其他频段。
