Coupled-Line Directional Coupler Using Artificial Transmission Line

인공전송선로를 이용한 결합선로 방향성 결합기

  • Received : 2015.07.03
  • Accepted : 2015.11.16
  • Published : 2015.11.30


In this paper, a coupled line directional coupler using an LUC(Low-pass filter Unit Cell) of artificial transmission line is presented. The conventional coupled line coupler is limited in length by the ${\lambda}/4$ transmission line while the proposed coupling structure is implemented smaller than $90^{\circ}$ by inserting the phase delay line between two coupled line, reduced in physical size by configuring a phase delay line with an LUC having the characteristics of a typical transmission line in a particular frequency. A coupler having -10 dB coupling factor at the center frequency of 700 MHz is designed, fabricated. The measured result agrees well with that of conventional one. The length of the fabricated coupled line coupler has about 45 % in length compared to the conventional one.


Coupled Line Directional Coupler;Artificial Transmission Line;Low-Pass Filter Unit Cell;Miniaturized Coupler


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