Novel Allpass Filter Configuration Employing Single OTRA

Cakir C., Cicekoglu O., ÇAM U.

IEEE Transactions on Circuits and Systems II: Express Briefs, vol.52, no.3, pp.122-125, 2005 (SCI-Expanded) identifier identifier

  • Publication Type: Article / Article
  • Volume: 52 Issue: 3
  • Publication Date: 2005
  • Doi Number: 10.1109/tcsii.2004.842055
  • Journal Name: IEEE Transactions on Circuits and Systems II: Express Briefs
  • Journal Indexes: Science Citation Index Expanded (SCI-EXPANDED), Scopus
  • Page Numbers: pp.122-125
  • Keywords: allpass filters, analog integrated circuits, operational transresistance amplifiers (OTRAs), OPERATIONAL TRANSRESISTANCE AMPLIFIER, ALL-PASS, CURRENT CONVEYOR
  • Dokuz Eylül University Affiliated: Yes


A new circuit configuration uses a single operational transresistance amplifier (OTRA) and four passive elements to realize both first- and second-order allpass filters. Owing to internal grounding of the OTRA input terminals, effects of input parasitics are significantly reduced. Applications of the circuit include the realization of the phase equalizer, the quadrature oscillator, and the high-Q bandpass filter for analog signal processing. The performance of the allpass filter is illustrated by circuit-level simulation of a quadrature oscillator with CMOS realization of the OTRA. © 2005, The Institute of Electrical and Electronics Engineers, Inc. All rights reserved.