A Novel and Compact Eight-Port Forward-Wave Directional Coupler With Arbitrary Coupling Level Design Using Four-Mode Control Technology

作者：Ting Hui Ling; Hsu Sen Kuei; Wu Tzong Lin^*

来源：IEEE Transactions on Microwave Theory and Techniques, 2017, 65(2): 467-475.

DOI：10.1109/TMTT.2016.2623709

• Coupled-line forward-wave directional coupler (FWDC)
• four-mode
• multiport coupler
• periodic structure
• power splitting/combining

We propose a novel, eight-port, forward-wave directional coupler with periodically patterned ground structures. The input impedances of the four modes for the proposed coupler can be matched, and the phase difference between the even-even and the other three modes is also strongly enhanced. Equivalent models have been constructed to predict the propagation properties based on the Bloch-Floquet theorem. A design procedure is also proposed completely based on the equivalent models. The proposed couplers, with both equal and unequal power divisions, are fabricated on a Duroid substrate. Then, there is good agreement between theoretical simulations and measurements.

• 出版日期2017-2