108-316- and 220-290-GHz Ultrabroadband Distributed Frequency Doublers

Iljin Lee, Younghwan Kim, Sanggeun Jeon

Research output: Contribution to journalArticlepeer-review

8 Citations (Scopus)


An analysis and design of distributed frequency doublers is presented at millimeter-wave (mm-wave) frequencies, including the D -, G -, and H -bands. The phase condition required for coherent output summation in the distributed multipliers is analyzed to maximize the output power and bandwidth. Based on the analysis, two mm-wave distributed frequency doublers are designed and experimentally demonstrated. The first doubler combines three unit cells in a distributed manner, while the insertion phase is equalized between the input and output artificial transmission lines (T-lines). A differential quasi-cascode structure is proposed for each unit cell, which enables the bandwidth extension and chip-size reduction. The differential doubler exhibits a measured peak output power and a conversion gain of 3.5 dBm and -2.5 dB, respectively, at the output frequency of 165 GHz. At 276 GHz, the output power and conversion gain are 1.6 dBm and -6.2 dB, respectively. The doubler maintains high output power above -5 dBm from 108 to 316 GHz, which covers almost the entire D -, G -, and H -bands. The second doubler combines five single-ended cascode unit cells to improve the output power and conversion gain. A bandpass filter is employed at the output T-line for spurious signal suppression. The single-ended doubler shows a measured peak output and conversion gain of 5.5 dBm and 0.3 dB, respectively, at 240 GHz. The bandwidth for -5-dBm output is from 220 to 290 GHz. Both doublers occupy a small chip area of 0.23 and 0.27 mm2, respectively, including all probing pads.

Original languageEnglish
Article number8922893
Pages (from-to)1000-1011
Number of pages12
JournalIEEE Transactions on Microwave Theory and Techniques
Issue number3
Publication statusPublished - 2020 Mar 1

Bibliographical note

Funding Information:
Manuscript received August 26, 2019; revised October 23, 2019; accepted October 26, 2019. Date of publication December 4, 2019; date of current version March 4, 2020. This work was supported by a grant to Terahertz Electronic Device Research Laboratory funded by Defense Acquisition Program Administration and by Agency for Defense Development (ADD) under Contract number UD180025RD. This article is an expanded version from the IEEE MTT-S International Microwave Symposium (IMS 2019), Boston, MA, USA, June 2-7, 2019. (Corresponding author: Sanggeun Jeon.) The authors are with the School of Electrical Engineering, Korea University, Seoul 02841, South Korea (e-mail: sgjeon@korea.ac.kr).

Publisher Copyright:
© 2019 IEEE.


  • Bandpass filter
  • broadband source
  • differential quasi-cascode pair
  • distributed structure
  • frequency doublers
  • millimeter-wave (mm-wave)

ASJC Scopus subject areas

  • Radiation
  • Condensed Matter Physics
  • Electrical and Electronic Engineering


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