A Design Methodology for Miniaturized Power Dividers Using Periodically Loaded Slow Wave Structure With Dual-Band Applications

This paper proposes an analytically-based approach for the design of a miniaturized single-band and dual-band two-way Wilkinson power divider. This miniaturization is achieved by realizing the power divider's impedance transformers using slow wave structures. These slow wave structures are designed by periodically loading transmission lines with capacitances, which reduces the phase velocity of the propagating waves and hence engender higher electric lengths using smaller physical lengths. The dispersive analysis of the slow wave structure used is included in the design approach to ensure a smooth nondispersive transmission line operation in the case of dual-band applications. The design methodology is validated with the design of a single-band, reduced size, two-way Wilkinson power divider at 850 and 620 MHz. An approximate length reduction of 25%-35% is achieved with this technique. For dual-band applications, this paper describes the design of a reduced size, two-way Wilkinson power divider for dual-band global system for mobile communications and code division multiple access applications at 850 and 1960 MHz, respectively. An overall reduction factor of 28%, in terms of chip area occupied by the circuit, is achieved. The electromagnetic simulation and experimental results validate the design approach. The circuit is realized with microstrip technology, which can be easily fabricated using conventional printed circuit processes.