In the mentioned article, Peng et al. proposed a three-port power divider (PD) and four-port coupler with tunable power division ratio based on: 1) cascade connection of 3-dB in-phased PD, matched tunable difference phase transmission lines (TLs), and 3-dB quadrature branch line coupler (QBLC) and 2) cascade connection of QBLC, mismatched in-phased TLs, and QBLC. However, the proposed four-port coupler provides an undesired phase difference of 90° between the output signals. Also, the scattering parameter analysis of the second design seems to be incorrect. In this letter, a correct approach is provided to analyze S-parameters.

中文翻译：

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《两种基于级联传输线的新型可重构PD》评述


在上述文章中，Peng 等人。提出了一种具有可调功率分配比的三端口功率分配器 (PD) 和四端口耦合器，其基于：1) 3dB 同相 PD、匹配的可调差相位传输线 (TL) 和 3dB 的级联正交支线耦合器 (QBLC) 和 2) QBLC、失配同相 TL 和 QBLC 的级联。然而，所提出的四端口耦合器在输出信号之间提供了不期望的 90° 相位差。此外，第二个设计的散射参数分析似乎不正确。在这封信中，提供了分析 S 参数的正确方法。