Design of bessel low pass filter using DGS with improved characteristics for RF/microwave applications

Ashwani Kumar*, A. K. Verma, Nainu P. Chaudhari

*Corresponding author for this work

Research output: Contribution to journalArticlepeer-review

1 Citation (Scopus)


We report a synthesis process to design the defected ground structure (DGS)-based Bessel lowpass filter (LPF). For 5-pole LPF at fc = 2.5 GHz, its selectivity is 10.6 dB/GHz and for the DGS-based Butterworth LPF it is 12.6 dB/GHz. For the lumped elements Bessel LPF, it is only 4.84 dB/GHz. Its 20 dB rejection bandwidth is 13.1 GHz and impedance matching BW is 76%, as against 88.8% for Butterworth LPF. At fc = 7.5 GHz, the 5-pole DGS Bessel LPF has selectivity 7 dB/GHz, 20 dB rejection BW is 13 GHz and 10 dB return loss (RL) BW in passband is 4.86 GHz (64.8%) with less than 7.9 pS group delay (GD) variation. In case of a bulky mixed microstrip-waveguide (MMW) 5-pole Bessel LPF at 7.5 GHz [W. Menzel and F. Boigelsack, 29th European Microwave Conference, Munich (1999), pp. 191-194.], reported results are: sharpness of cut-off 1.48 dB/GHz, 10 dB RL BW and GD variation are 48% and 4 pS, respectively. The improved performance the DGS-based Bessel LPF can find applications in high speed data communication, front-end of a wideband communication system and in a power amplifier, by improving the selectivity, suppression of harmonics and linear distortion.

Original languageEnglish
Article number1450122
Pages (from-to)1-25
Number of pages25
JournalJournal of Circuits, Systems and Computers
Issue number9
Publication statusPublished - Oct 2014
Externally publishedYes


  • Bessel low pass filter
  • defected ground structure (DGS)
  • group delay (GD)
  • microstrip


Dive into the research topics of 'Design of bessel low pass filter using DGS with improved characteristics for RF/microwave applications'. Together they form a unique fingerprint.

Cite this