Wideband Noise Measurement Technique in Duplex Systems for RF Interference

Chulsoon Hwang*, David Pommerenke, Jun Fan, Takashi Enomoto, Junji Maeshima, Kenji Araki

*Corresponding author for this work

Research output: Contribution to journalArticlepeer-review


A wideband noise measurement technique with improved isolation is demonstrated for a practical mobile phone. The liquid crystal display (LCD) baseband noise modulated with a transmitted radio frequency (RF) signal interferes with the received RF signal, resulting in an RF desensitization problem. A wideband and simple measurement setup based on a 180° hybrid coupler is proposed and demonstrated to characterize the modulation and its coupling behaviors in duplex systems. This setup overcomes the frequency limitation of a duplexer-based measurement setting. In addition, signal-to-noise ratio improvement in the proposed measurement technique is quantitatively analyzed.

Original languageEnglish
Pages (from-to)1038-1044
Number of pages7
JournalIEEE Transactions on Electromagnetic Compatibility
Issue number4
Publication statusPublished - 1 Aug 2018
Externally publishedYes


  • Electromagnetic interference
  • liquid crystal display (LCD)
  • mobile phone
  • modulation
  • radio frequency (RF) interference

ASJC Scopus subject areas

  • Atomic and Molecular Physics, and Optics
  • Condensed Matter Physics
  • Electrical and Electronic Engineering

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