A $\pi$-type Variable Attenuator with Low Phase Shift

저위상 변화 특성을 갖는 $\pi$-형 가변 감쇠기

  • 박웅희 (강원대학교 삼척캠퍼스 전자공학과) ;
  • 안길초 (서강대학교 전자공학과)
  • Published : 2009.10.31

Abstract

A voltage controlled attenuator using a PIN diode and two resistors of the $\pi$-type fixed attenuator is described in this paper. The proposed variable attenuator operating for a fixed attenuation range has a good input VSWR and a low intermodulation signal. For the low phase shift, a PIN diode is connected with open stub for the purpose of phase compensation. The stub for phase compensation is calculated by the Deloach method and the related circuit theory. This attenuator is easily fabricated on the microstrip and can be normally used in fine control circuits within small attenuation range. The fabricated attenuator for 2110~2170 MHz frequency band has about 4 dB of an attenuation range, $2^{\circ}$ of phase variance, and -20 dB of S11 according to the input voltage from 0 to 2.7 V.

References

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