CPW Phase Shifter and Shunt Stub with Air-Bridge Fabricated on Oxidized Porous Silicon(OPS) Substrate

산화된 다공질 실리콘 기판 위에 제작된 에어브리지를 가진 CPW Phase Shifter와 Shunt Stub

  • Sim, Jun-Hwan (Division of Radio and Information Communication Engineering, Korea Maritime University) ;
  • Park, Dong-Kook (Division of Radio and Information Communication Engineering, Korea Maritime University) ;
  • Kang, In-Ho (Division of Radio and Information Communication Engineering, Korea Maritime University) ;
  • Kwon, Jae-Woo (School of Electrical Engineering and Computer Science, Kyungpook National University) ;
  • Park, Jeong-Yong (School of Electrical Engineering and Computer Science, Kyungpook National University) ;
  • Lee, Jong-Hyun (School of Electrical Engineering and Computer Science, Kyungpook National University) ;
  • Jeon, Joong-Sung (Research Institute of Industrial Technology, Korea Maritime University) ;
  • Ye, Byeong-Duck (Division of Maritime Transportation Science, Korea Maritime University)
  • 심준환 (韓國海洋大學校 電波情報通信工學部) ;
  • 박동국 (韓國海洋大學校 電波情報通信工學部) ;
  • 강인호 (韓國海洋大學校 電波情報通信工學部) ;
  • 권재우 (慶北大學校 電子電氣컴퓨터工學部) ;
  • 박정용 (慶北大學校 電子電氣컴퓨터工學部) ;
  • 이종현 (慶北大學校 電子電氣컴퓨터工學部) ;
  • 전중성 (韓國海洋大學校 産業技術硏究所) ;
  • 예병덕 (韓國海洋大學校 海事輸送科學部)
  • Published : 2002.09.01

Abstract

This paper presents a CPW phase shifter and shunt stub with air-bridge on a 10-${\mu}m$-thick oxidized porous silicon(OPS) substrate using surface micromachining. The line dimensions of the CPW phase shifter was designed with S-W-Sg = 100-30-400 ${\mu}m$. And the width and length of the air-bridge with "ㄷ“ shape were 100 ${\mu}m$ and 400-460-400 ${\mu}m$, respectively. In order to achieve low attenuation, stepped air-bridge CPW phase shift was proposed. The insertion loss of the stepped air-bridge CPW phase shift is more improved than that of no stepped air-bridge CPW phase shift. The measured phase characteristic of the fabricated CPW phase shifter is close to 180$^{\circ}$ over a very broad frequency range of 28 GHz. The measured working frequency of short-end series stub is 28.7 GHz and the return loss is - 20 dB. And the measured working frequency of short-end shunt stub is 28.9 GHz and the return loss is - 23 dB at midband. As a result, the pattering of stub in the center conductor of CPW lines can offer size reduction and lead to high density chip layouts.

본 논문에서는 표면 마이크로머시닝을 사용하여 10 ${\mu}m$ 두께의 다공질 실리콘 산화막으로 제조된 기판 위에 에어브리지를 가진 CPW phase shifter와 shunt stub을 제작하였다. CPW phase shifter의 크기는 S-W-$S_g$ = 100-30-400 ${\mu}m$로 설계되었다. “ㄷ” 모양을 가진 에오브리지의 폭은 100 ${\mu}m$, 길이는 400-460-400 ${\mu{m$ 이다. 낮은 손실을 얻기 위하여, step 된 에어브리지를 가진 CPW phase shifter가 제안되었다. Step된 에어브리지를 가진 구조가 step이 없는 에어브리지를 가진 구조보다 삽입손실이 보다 더 향상되었다. 제작된 CPW phase shifter의 위상특성은 28 GHz의 넓은 주파수 범위에서 180$^{\circ}$ 의 천이를 나타내었다. 그리고 short-end series stub의 동작주파수는 28.7 GHz이며, 반사손실은 - 20 dB를 나타내었다. 또한 short-end shunt stub의 동작주파수는 28.9 GHz이며, 반사손실은 - 23 dB를 나타내었다. 이상의 결과에서 중앙 전송선에 설계된 stub은 크기 감소로 고 밀도 칩 레이아웃을 이끌 수 있는 장범을 가진다.

Keywords

References

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