A Dual-Mode Power Divider With Embedded Meta-Materials and Additional Grounded Resistors

This article presents a dual-mode power divider (PD) that offers new working mechanism, compact size, significant design freedom, wide working bandwidth, arbitrary power division, and ultrawide isolation between the two output ports. The structure is simple in comparison with conventional Wilkinson PDs in that only two composite right-and left-handed (CRLH) transmission lines (TLs) grounded through two resistors are used. Different from previous CRLH-TL-embedded studies in that almost all CRLH-TLs operate at quarter-wavelength phase responses, in the present work, the zero-degree property is noted and used to modify the impedance variation curves. Additionally, because of the use of grounded resistors, the proposed PD can operate in two modes, such that when high-value resistors are used, the PD operates in a lossless mode, while when low-value resistors are used, the PD operates in an attenuated mode. Because working power has been significantly improved due to progress in modern RF system development, more attenuation elements are required. This means that attenuated PDs will become very useful in the future. For verification, two PDs operating in different working modes and power divisions are designed and fabricated. Based on the experimental results, both PDs demonstrate good performance over more than 60% of the bandwidth with reference to the 15-dB $S_{11}$ , ultrawide isolation, full port matching, and compact size.