Novel Quadrature Branch-line Coupler Using CPW-to-Microstrip Transitions

마이크로스트립 전이를 이용하는 CPW Branch-line 커플러

  • 이중호 (아주대학교 전기전자공학부) ;
  • 이해영 (아주대학교 전기전자공학부)
  • Published : 2000.05.01

Abstract

This paper presents new double-sided 3-dB branch-line coupler using CPW-to-Microstrip via-hole transitions for the multi-layer applications. The characteristic impedance is obtained using the even-odd mode method, and the circuit performance Is accurately estimated by the Finite Difference Time Domain(FDTD) method. The fabricated double-sided 3-dB branch-line coupler has less than 0.3 dB power dividing imbalance and 1。 phase imbalance, greater than 30 dB isolation, and 25 dB return loss over a 20% bandwidth centered at 2 GHz. Calculated and fabricated results show that this coupler provides better performance as compared to the conventional microstrip branch-line couplers.

본 논문에서는 초고주파 집적회로에서 일반적으로 사용되는 90。 branch-line 커플러를 CPW와 마이크로 스트립의 다른 두 전송선이 조합된 형태로 구성하였다. 4포트 회로망에 대해서 even-odd 모드 해석 방법을 통해서 전송선들의 적절한 특성 임피던스를 결정하고, 효과적으로 전송선의 특성을 예측할 수 있는 유한 차분법 시간 영역 방법으로 전체 구조에 대해서 계산하였다 그리고 실제 제작 및 측정을 통해서 계산과 측정 결과가 잘 일치함을 화인하였다. 새롭게 제안된 커플러는 기존의 커플러의 비해 동작 주파수에서 두 출력 포트로 전력이 균등히 분배되고, 위상차가 90。로 유지되는 등 매우 우수한 성능을 가짐을 확인하였다.

Keywords

References

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