Optimization-free design equations for narrowband equal-division filtering power divider with pre-specified filtering response and wideband isolation

Boyoung Lee, Seunggoo Nam, Juseop Lee

Research output: Contribution to journalArticlepeer-review

13 Citations (Scopus)


In this paper, we present completely analytic design equations for a narrowband filtering power divider with an excellent isolation performance over a wide frequency range. For providing the complete design equations, the even-odd mode analysis on the circuits has been carried out. The design theory and equations allow a filtering power divider containing frequency-independent inverters to have infinite isolation over the entire frequency range. The presented design theory is significant in a sense that it enables designing a filtering power divider with a high isolation over a wide frequency range when the divider contains frequency-variant inverters in practice. Using the closed-form equations, all circuit element values and detailed physical dimensions of filtering power divider can be found based on a pre-specified filtering response. Therefore, our design method can provide a filtering power divider design guideline for the various specifications required by communications systems. For verifying the presented design method and analytic design equations, a third-order lumped-element narrowband filtering power divider has been designed, fabricated, and measured. We have also implemented a filtering power divider using microstrip resonators to verify that the presented design method and equations can be applied to distributed-element filtering power divider designs. The measured results have shown a good agreement with theoretical results.

Original languageEnglish
Pages (from-to)2496-2507
Number of pages12
JournalIEEE Transactions on Circuits and Systems I: Regular Papers
Issue number7
Publication statusPublished - 2019

Bibliographical note

Funding Information:
Manuscript received August 18, 2018; revised December 2, 2018 and January 22, 2019; accepted January 27, 2019. Date of publication March 1, 2019; date of current version June 18, 2019. This work was supported by the Korean Government (MSIT) through National Research Foundation of Korea (NRF) under Grant NRF-2018R1A2B6006095. This paper was recommended by Associate Editor C. Li. (Corresponding author: Juseop Lee.) The authors are with the College of Informatics, Korea University, Seoul 02841, South Korea (e-mail: juseoplee@gmail.com).

Publisher Copyright:
© 2019 IEEE.


  • Design equations
  • Design theory
  • Filtering power divider
  • Wide isolation performance

ASJC Scopus subject areas

  • Electrical and Electronic Engineering


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