Design procedure for active microwave filters using the high quality active negative capacitance circuit for rf low-noise bandpass applications

Kaya A.

MICROWAVE AND OPTICAL TECHNOLOGY LETTERS, vol.50, no.4, pp.1086-1093, 2008 (Peer-Reviewed Journal) identifier identifier

  • Publication Type: Article / Article
  • Volume: 50 Issue: 4
  • Publication Date: 2008
  • Doi Number: 10.1002/mop.23296
  • Journal Indexes: Science Citation Index Expanded, Scopus
  • Page Numbers: pp.1086-1093


This article presents a new methodology based on active band pass filter. In the proposed design, a resonator consists of an active negative capacitor together with a conventional inductor represented. The active negative capacitor is made of a field-effect transistor that exhibits negative capacitance and negative resistance. It can, therefore, compensate the loss of an inductor. Two pole active bandpass filter centered 1.3 GHz, with 3 dB bandwidth of 640 MHz, high gain 1.5 dB, including a very low-noise active filter which exhibits a noise figure of 2.5 dB are realized in the fist part. Compared with the conventional BPF the proposed design shows better gain, noise figure, and the return loss level. (C) 2008 Wiley Periodicals, Inc.