A mm-wave stub-loaded ECPW Wilkinson power divider/combiner in 90 nm CMOS

Chueh Yu Kuo, Austin Ying Kuang Chen, Changzhi Li, Ching Hsing Luo

Research output: Contribution to journalArticlepeer-review

12 Scopus citations


This letter presents a millimeter-wave (mm-wave) slow-wave elevated coplanar waveguide (ECPW) power divider/combiner fabricated in the back-end-of-the-line (BEOL) of a 90 nm CMOS technology. Design techniques using periodical loading stubs and elevated signal conductors are applied toward the CPWs that enable i) an aggressive size-reduction by increasing the artificial effective dielectric constant (εeff) ii) realization of high-impedance transmission lines at mm-wave. The measurement results reveal that the insertion loss is 2.3 and 2.4 dB at 60 and 67 GHz, respectively. The measured isolation of over 13 dB is observed from 59 GHz to at least 110 GHz. The divider also achieves an excellent amplitude imbalance and phase imbalance of less than 0.16 dB and less than 0.45°, respectively, up to 67 GHz (limited by test setup). The core size of the proposed divider is only 205 μm × 250 μm (0.051 mm2) equivalent to a size-reduction of over 70% compared to a conventional Wilkinson power divider. To the best of authors' knowledge, this is the first Wilkinson power divider/combiner that has demonstrated the highest operating frequency characterized among all other known semiconductor technologies reported.

Original languageEnglish
Article number2226937
Pages (from-to)627-629
Number of pages3
JournalIEEE Microwave and Wireless Components Letters
Issue number12
StatePublished - 2012


  • CMOS
  • Wilkinson power divider/combiner
  • elevated CPW
  • millimeter-wave (mm- wave)
  • slow-wave (SW)


Dive into the research topics of 'A mm-wave stub-loaded ECPW Wilkinson power divider/combiner in 90 nm CMOS'. Together they form a unique fingerprint.

Cite this