In this study, a novel quasi-transverse electromagnetic (TEM) transmission line (TL) on a single-layer substrate is presented. The proposed structure comprises bilateral metalised vias and two longitudinal slots on the top and bottom plates, respectively. This two-conductor TL separated by the two slots allows the quasi-TEM mode and guarantees high isolation due to the vias which constrain the electromagnetic field. Additionally, the proposed structure provides a remarkable high range of the characteristic impedance, enabling a more flexible design. Furthermore, an empirical analytical formula is derived to calculate the characteristic impedance of the proposed TL adopting conformal mapping, and modified by a polynomial fraction. The transitions to the double-sided parallel-strip line and the microstrip line are proposed with which the propagation constant of this TL is extracted. The comparisons of the far-end couplings of several types of microwave TLs have been provided by the simulation and measurement to verify the isolation property of the proposed TL. Finally, the proposed TL is applied to the T-junction wideband power divider design to demonstrate its practicability. A prototype is fabricated and measured with a wide operating bandwidth from 6.8 to 17.6   GHz.

中文翻译：

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高隔离度新型平面准TEM传输线及其在T型结功率分配器中的应用

在这项研究中，提出了一种新颖的单层基板上的准横向电磁（TEM）传输线（TL）。所提出的结构包括双向金属化通孔以及分别在顶板和底板上的两个纵向槽。由两个槽隔开的该双导体TL允许准TEM模式，并由于过孔限制了电磁场，从而保证了高隔离度。另外，所提出的结构提供了很大的特性阻抗范围，从而实现了更灵活的设计。此外，推导了经验解析公式，采用共形映射的方法计算了所提出的TL的特性阻抗，并通过多项式分数进行了修正。提出了向双面平行带状线和微带状线的过渡，利用该过渡可以提取该TL的传播常数。通过仿真和测量对几种类型的微波TL的远端耦合进行了比较，以验证所提出TL的隔离特性。最后，将所提出的TL应用于T型结宽带功率分配器设计，以证明其实用性。制作并测量了原型，并具有从6.8到17.6的宽工作带宽 拟议的TL应用于T型结宽带功率分配器设计，以证明其实用性。制作并测量了原型，并具有从6.8到17.6的宽工作带宽 拟议的TL应用于T型结宽带功率分配器设计，以证明其实用性。制作并测量了原型，并具有从6.8到17.6的宽工作带宽   GHz。