, 44:111 | Cite as

Miniaturized composite band pass filter using folded transmission lines for wideband radar

  • Somsing RathodEmail author
  • Atul Kumar
  • K S Beenamole
  • K P Ray


A composite design of Band Pass Filter (BPF) is developed with 3-dB fractional bandwidth (FBW) of more than 140%. This BPF is suitable for the development of wideband radar, communication and EW system in 1 to 6 GHz. Composite BPF design utilizes stepped impedance Low Pass Filter (LPF) along with the quarter wavelength (λg/4) short circuited stub. λg/4 short circuited stubs incorporated High Pass Filter (HPF) response which transforms overall design into BPF. Four cases of filter have been discussed. In case-I, the proposed BPF is developed with a size of 32.6 mm X 7.0 mm. Further in case-II, design has been realized with improved roll-off at the lower edge of the bandwidth (i.e., 1GHz). In case-III, developed design is 75% length-wise miniaturized that of case-I. Further in case-IV, about 55% length-wise miniaturization is done. Case-III and IV have their response similar to that of the case-I with miniaturized design. All designs are simulated, optimized and fabricated over RT-Duroid 5880 substrate. For case-I, III and IV fabrication has been done on 20 mil thick substrate, whereas for case-II 31 mil thick substrate is used. Comparisons between all the cases have been presented in tables and S-parameter plots.


Band pass filter electronic warfare radar receiver ultra wideband composite filter 


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Copyright information

© Indian Academy of Sciences 2019

Authors and Affiliations

  1. 1.Electronic and Radar Development Establishment (LRDE)BangaloreIndia
  2. 2.Defence Institute of Advanced Technology (DIAT)PuneIndia

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