Compact CCITL-Inspired Power Divider Design Using Multisection Transmission Lines

This work provides a comprehensive review of conjugately characteristic impedance transmission lines (CCITLs) and their applications in quarter-wave–like transformers (QWLTs). These promising concepts are employed in the development of miniaturized CCITL-based power dividers (CCITL-PDs). A thorough design procedure for CCITL-PDs with arbitrary power division ratios is presented, including detailed derivations and analysis of the perfect isolation condition. For illustration, an equal-split CCITL-PD implemented using multisection transmission lines (MSTLs) is designed to achieve a 25% reduction in electrical length compared to conventional equal-split Wilkinson power dividers. Although the achieved reduction is modest, this example provides valuable insights and approaches for further optimizations in CCITL-PD design, showcasing its potential for microwave component miniaturization.