A polyphase filter based on CMOS inverters

Fred Tillman, Henrik Sjöland

Research output: Chapter in Book/Report/Conference proceedingPaper in conference proceedingpeer-review

11 Citations (SciVal)


A new idea for generation of quadrature signals on chip is presented. The topology is based on a passive RC polyphase filter, where the resistive parts are made active by using inverters. The active filter combines quadrature generation, isolation, and gain without losing quadrature performance compared to a regular RC polyphase filter. The filter technique is demonstrated in a 10GHz front-end application where a broadband VCO drives an active polyphase filter to generate quadrature LO signals. By avoiding a quadrature VCO and tuned buffers, significant reductions in chip area are possible
Original languageEnglish
Title of host publication[Host publication title missing]
PublisherIEEE - Institute of Electrical and Electronics Engineers Inc.
ISBN (Print)1-4244-0064-3
Publication statusPublished - 2005
EventNORCHIP Conference, 2005 - Oulu, Finland
Duration: 2005 Nov 212005 Nov 22


ConferenceNORCHIP Conference, 2005

Subject classification (UKÄ)

  • Electrical Engineering, Electronic Engineering, Information Engineering


  • active filter
  • quadrature generation
  • 10 GHz
  • passive RC filter
  • tuned buffers
  • quadrature LO signals
  • voltage controlled oscillator
  • polyphase filter
  • CMOS inverters


Dive into the research topics of 'A polyphase filter based on CMOS inverters'. Together they form a unique fingerprint.

Cite this