X- and ku-band amplifiers based on si/sige hbt's and micromachined lumped components

Jae Sung Rieh, Liang Hung Lu, Linda P.B. Katehi, Pallab Bhattacharya, Edward T. Croke, George E. Ponchak, Samuel A. Alterovitz

Research output: Contribution to journalArticlepeer-review

53 Citations (Scopus)


A double mesa-structure Si/SiGe heterqjunction bipolar transistor (HBT) and novel niicrornachined lumped passive components have been developed and successfully applied to the fabrication of X- and Ku-band monolithic amplifiers. The fabricated 5 × 5 μm2 emitter-size Si/SiGe HBT exhibited a de-current gain β of 109, and fT and fmax of 28 and 52 GHz, respectively. Micromachined spiral inductors demonstrated resonance frequency of 20 GHz up to 4 nH, which is higher than that of conventional spiral inductors by a factor of two. Single-, dual-, and three-stage X-band amplifiers have been designed, based on the extracted active- and passive-device model parameters. A single-stage amplifier exhibited a peak gain of 4.0 dB at 10.0 GHz, while dual- and three-stage versions showed peak gains of 5.7 dB at 10.0 GHz and 12.6 dB at 11.1 GHz, respectively. A Ku-band single-stage amplifier has also been designed and fabricated, showing a peak gain of 1.4 dB at 16.6 GHz. Matching circuits for all these amplifiers were implemented by lumped components, leading to a much smaller chip size compared to those employing distributed components as matching elements.

Original languageEnglish
Pages (from-to)685-694
Number of pages10
JournalIEEE Transactions on Microwave Theory and Techniques
Issue number5 PART 2
Publication statusPublished - 1998
Externally publishedYes

Bibliographical note

Funding Information:
Manuscript received December 31, 1997; revised February 11, 1998. This work was supported by NASA-Cleveland under Grant NAG3-1903 and by the Air Force Office of Scientific Research under Grant F49620-95-1-0013. J.-S. Rieh, L.-H. Lu, L. P. B. Katehi, and P. Bhattacharya are with the Department of Electrical Engineering and Computer Science, The University of Michigan, Ann Arbor, MI 48109-2122 USA. E. T. Croke is with Hughes Research Laboratory, Malibu, CA 90265 USA. G. E. Ponchak and S. A. Alterovitz are with NASA Lewis Research Center, Cleveland, OH 44135 USA. Publisher Item Identifier S 0018-9480(98)03395-X.

Funding Information:
Dr. Bhattacharya is a member of the American Physical Society and Sigma Xi. He is an editor of the IEEE TRANSACTIONS ON ELECTRON DEVICES. He received the Parker Rhodes Scholarship from the University of Sheffield, the Research Excellence Award from the University of Michigan, and the Alexander von Humboldt Award.


  • Amplifier
  • HBT
  • MMIC
  • Micromachining
  • Resonance frequency
  • Sige

ASJC Scopus subject areas

  • Radiation
  • Condensed Matter Physics
  • Electrical and Electronic Engineering


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