400 GHz HBT differential amplifier using unbalanced feed networks

J. Hacker, M. Urteaga, R. Lin, A. Skalare, I. Mehdi, J. S. Rieh, M. Kim

Research output: Contribution to journalArticlepeer-review

15 Citations (Scopus)


A terahertz differential eight-stage amplifier fabricated using state-of-the-art 125 nm double-heterojunction bipolar transistors (DHBT) is presented. The four-port unit-cell chain is designed for optimum forward differential gain with no even and odd-mode reverse gains. Unbalanced single-ended feed networks are added to preserve the amplifier gain without inducing oscillations. The proposed feed scheme is validated by a stable amplifier operation in 325-to-450 GHz range with the peak gain of 22 dB at 375 GHz.

Original languageEnglish
Article number6293920
Pages (from-to)536-538
Number of pages3
JournalIEEE Microwave and Wireless Components Letters
Issue number10
Publication statusPublished - 2012

Bibliographical note

Funding Information:
Manuscript received March 06, 2012; revised June 21, 2012 and August 06, 2012; accepted August 17, 2012. Date of publication August 31, 2012; date of current version October 03, 2012. This work was supported by the KCC (Korea Communications Commission) under the R&D program supervised by the KCA (Korea Communications Agency) [KCA-2012-12-911-01-101]. J. Hacker and M. Urteaga are with the Teledyne Scientific Company, Thousand Oaks, CA 91360 USA. R. Lin, A. Skalare, and I. Mehdi are with the Jet Propulsion Laboratory, Pasadena, CA 91125 USA. J.-S. Rieh and M. Kim are with the School of Electrical Engineering, Korea University, Seoul 136-701, Korea (e-mail: mkim@korea.ac.kr). Digital Object Identifier 10.1109/LMWC.2012.2214767 Fig. 1. Differential amplifier block diagram consisting of the unit-cell chain and two unbalanced feed networks.


  • Differential feed
  • InP HBT
  • Terahertz amplifier

ASJC Scopus subject areas

  • Condensed Matter Physics
  • Electrical and Electronic Engineering


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