A compact quadrature coupler based on coupled artificial transmission lines

@article{Liu2005ACQ,
  title={A compact quadrature coupler based on coupled artificial transmission lines},
  author={Zhiyang Liu and R. M. Weikle},
  journal={IEEE Microwave and Wireless Components Letters},
  year={2005},
  volume={15},
  pages={889-891}
}
A new compact quadrature hybrid based upon artificial transmission lines (ATLs) is presented. Miniaturization is achieved through reduced even- and odd-mode phase velocities which are achieved using capacitive loading with interdigital open-circuited stubs. A proof-of-concept microstrip implementation of the quadrature hybrid exhibits performance comparable to a conventional branch-line coupler while occupying only 14% of the area. The compact structure of the hybrid is useful for RF… CONTINUE READING