Analysis of a finite length microstripegative-refractive-index coupled-line coupler

摘要

The scattering parameters of finite-length MS/NRI coupled-line couplers are derived analytically using coupled-mode theory. Harnessing this theory, a -25dB high-directivity planar coupler is designed and tested experimentally having a directivity around 35 dB over a 100MHz bandwidth centered at 1.75GHz.