A 220-320-GHz vector-sum phase shifter using single Gilbert-cell structure with lossy output matching

Younghwan Kim, Sooyeon Kim, Iljin Lee, Miguel Urteaga, Sanggeun Jeon

Research output: Contribution to journalArticlepeer-review

35 Citations (Scopus)


This paper presents a wideband vector-sum phase shifter (VSPS) that operates over the entire WR-3 band (220-320 GHz). Compared to conventional VSPSs with double Gilbert cells, the proposed phase shifter employs a single Gilbert-cell structure for vector modulation. This reduces the output current combining ratio from 8:2 to 4:2, and boosts the impedance at the combining node, thus facilitating wideband output matching at upper millimeter-wave and terahertz bands. The simplified structure leads to a reduction in dc power consumption and chip area without sacrificing the 360° phase-shifting property. Lossy matching is applied at the Gilbert-cell output to further increase bandwidth and stability at the expense of relatively high loss. The phase shifter is implemented using a 250-nm InP DHBT technology that provides fT and fmax exceeding 370 and 650 GHz, respectively. The measurements exhibit a wideband phase shift with continuous 360° coverage and average insertion loss ranging from 11.8 to 15.6 dB for the entire WR-3 band. The root mean square amplitude and phase error among different phase states are less than 1.2 dB and 10.2°, respectively. The input-referred 1-dB compression is measured at 0.7 dBm on average. The dc power consumption is 21.8-42.0 mW at different phase states.

Original languageEnglish
Article number6979282
Pages (from-to)256-265
Number of pages10
JournalIEEE Transactions on Microwave Theory and Techniques
Issue number1
Publication statusPublished - 2015 Jan 1

Bibliographical note

Publisher Copyright:
© 2014 IEEE.


  • Beam forming
  • InP DHBT
  • WR-3 band
  • lossy matching
  • single Gilbert-cell structure
  • vector-sum phase shifter (VSPS)

ASJC Scopus subject areas

  • Radiation
  • Condensed Matter Physics
  • Electrical and Electronic Engineering


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