Design and Fabrication of Wideband Millimeter-Wave Directional Couplers With Different Coupling Factors Based on Gap Waveguide Technology
Design and Fabrication of Wideband Millimeter-Wave Directional Couplers With Different Coupling Factors Based on Gap Waveguide Technology
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基于间隙波导技术的不同耦合系数宽带毫米波定向耦合器的设计与制作
DOI：
10.1109/access.2019.2926233
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发表时间：
2019
期刊：
影响因子：
3.9
通讯作者：
A. Zaman
中科院分区：
文献类型：
--
作者：
D. Zarifi;A. Farahbakhsh;A. Zaman
本文提出了一类适用于实现不同耦合水平的宽带定向耦合器。所提出的耦合器已实现使用双层槽隙波导在毫米波频率范围。它们由两个彼此叠置的平行槽隙波导部分组成，使得两个波导部分之间的耦合可以通过设置在公共壁中的耦合结构实现。通常，耦合层由两排孔组成，并且可以根据孔的数量来控制耦合水平。所提出的定向耦合器的明显和可应用的特性是，可以使用不同的耦合层简单地改变耦合水平，而不改变顶部和底部槽波导和过渡。作为所提出的耦合器的另一个显著优点，在结构的不同金属部分之间不需要良好的电接触，这大大简化了毫米波应用中的制造工艺和机械组装。为了验证的目的，三个样品耦合器的耦合水平为10，20，和30 dB的设计，制造和测量。为了使用标准矩形波导使器件可访问和可测量，设计了从槽隙波导到标准WR-15的两种类型的过渡。仿真结果与实验结果吻合良好，表明所设计的耦合器在50-70 GHz频段内具有较大的带宽，回波损耗水平为20 dB，耦合水平为10±1、20±1和30±1 dB，隔离水平为30、35和40 dB。所提出的定向耦合器可以用作毫米波频率的探测和紧凑的集成微波电路和系统，如天线阵列馈电网络的设计的良好候选人。
A class of wideband directional couplers suitable for achieving different coupling levels are proposed in this paper. The proposed couplers have been implemented using the double-layer groove gap waveguide at the millimeter-wave frequency range. They are composed of two parallel groove gap waveguide parts placed on top of each other in such a way that the coupling between the two waveguide sections can be achieved via the coupling structures placed in the common wall. Usually, the coupling layer consists of two rows of holes and depending on the number of holes the coupling levels can be controlled. The manifest and applicable property of the proposed directional coupler is that the coupling level can be simply changed using the different coupling layers without changing the top and bottom groove waveguides and transitions. As another significant advantage of the proposed coupler, there is no requirement of good electrical contact among different metallic parts of the structure, which considerably simplifies the manufacturing processes and mechanical assembly at millimeter-waves applications. For verification purpose, three sample couplers with coupling levels of 10, 20, and 30 dB have been designed, fabricated, and measured. To make the device accessible and measurable using the standard rectangular waveguides, two types of transitions from the groove gap waveguide to standard WR-15 are designed. The simulation and experimental results are in good agreement and show that the proposed couplers have large bandwidth for return loss level of 20 dB, coupling level of 10±1, 20±1, and 30±1 dB, and isolation level of 30, 35, and 40 dB over the desired frequency band of 50–70 GHz. The proposed directional couplers can be used as good candidates at millimeter-wave frequencies for probing and the design of compact integrated microwave circuits and systems, such as antenna array feeding networks.