Design a Modified Hairpin Filter for Wider Bandwidth
Abhinav V. Deshpande *
School of Electronics Engineering (SENSE), Vellore Institute of Technology (VIT), Vellore, Tamil Nadu, 632014, India.
*Author to whom correspondence should be addressed.
Abstract
This research paper presents the design and analysis of a micro strip hairpin band pass filter. A modified design of a band pass filter with a typical hairpin structure has been proposed. By adjusting the tapping positions and the gaps in between the hairpin resonators, a wider band pass filter is obtained. The fabricated band pass filter offers the measured bandwidth from 2.8 GHz and 3.9 GHz that is 1.1 GHz at a return loss of -10 db. The trial version of Ansoft HFSS software is used to carry out the simulation of the hairpin band pass filter. The group delay and the phase variations have also been measured in order to ascertain the quality of the pulse which is transmitted through the filer. The filter was fabricated on the FR4 substrate which is having a dielectric constant εr = 4.4 and the substrate thickness is of 1.53 mm. Such type of filter can be very useful for a portable communication system.
Keywords: Hairpin resonator, band pass filter, micro strip, return loss, insertion loss, band stop filter