A compact and wideband microstrip rat-race coupler employing two-section ring and artificial transmission lines (ATLs) is reported in this paper. The bandwidth is highly improved by using a two-section rat-race coupler. The physical size of the planar circuit is reduced based on the substitution of the microstrip line with an ATL. The area of the proposed design footprint is 35% of the area of the conventional similar design. The proposed coupler operates over a frequency range of 0.9 GHz to 1.85 GHz. In the desired band, the maximum measured amplitude imbalance is 0.6 dB, the phase variation is ± 7°, and the measured return loss is greater than 15 dB with isolation better than 20 dB. The prototype has been fabricated and measured, and the results are compared with the simulated data to validate the theory.

本文报道了一种紧凑的宽带微带大鼠－种族耦合器，该耦合器采用两段式环形传输线和人工传输线（ATL）。通过使用两段式大鼠种族耦合器，可以大大提高带宽。基于用ATL替代微带线，可以减小平面电路的物理尺寸。拟议的设计占地面积为常规类似设计面积的35％。拟议的耦合器在0.9 GHz至1.85 GHz的频率范围内工作。在所需频带中，最大测得的幅度不平衡度为0.6 dB，相位变化为±7°，测得的回波损耗大于15 dB，隔离度优于20 dB。原型已被制造和测量，并将结果与​​模拟数据进行比较以验证该理论。