Compact Equal and Unequal Dual-Frequency Power Dividers Based on Composite Right-/Left-Handed Transmission Lines

A novel approach using fully integrated composite right-/left-handed (CRLH) transmission lines (TLs) is proposed to design equal and unequal dual-frequency Wilkinson power dividers (WPDs) with controllable frequency ratio. Theoretical analysis indicates that the frequency ratio and the power-splitting ratio k² of the divider can be controlled by changing the element values and the number of the constructing cells of the CRLH TLs. Design formulas are presented to calculate the element values of the cells for a given frequency ratio. Dispersion relation, transmission/reflection coefficient, and Bloch impedance studies show that the Π-shaped unit cells have smaller size than the T-shaped counterparts but the same performance. For demonstration, one equal and one unequal dual-frequency WPDs operating at 2.45 and 5.2 GHz, respectively, are implemented. Measurements show that both the equal and unequal dividers have 17.5% and 26% relative bandwidths at 2.45 and 5.2 GHz, respectively.