3. Performance Evaluation and Optimization of Stepped Impedance and Stub-based Low-pass Filters for S-Band Applications 

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Naureen Butt, Ayesha Jaffar, Zeeshan Azmat Shaikh.


Wireless Communication is an integral part of modern communication systems. Microwave filters play a vital role in mobile and wireless communication systems. Microwave filters are used in most wireless communication systems having RF-front end for performing various signal processing tasks such as frequency selection, suppression of mixers unwanted intermodulation products etc. This paper presents the optimized design of low-cost microstrip technology based S-band low-pass filters using two different design topologies like: stepped impedance and stub-based filters. Low-pass filters of order N=5 are designed, optimized and simulated using the ADS tool to achieve minimum insertion loss (S21) in pass-band and attenuation greater than 20dB at 3.5GHz.Consequently, optimized filters are manufactured and tested using Vector Network Analyzer (VNA) for S21 parameter of device under test (DUT) . Finally, comparison of post simulation and measured results are carried out for the proposed filters.

Index Terms:

FR-4 substrate, Kuroda’s identities, Microstrip low-pass filter, Richard’s transforms, Stepped impedance

Cite this: Naureen Butt, Ayesha Jaffar, Zeeshan Azmat Shaikh, “ Performance Evaluation and Optimization of Stepped Impedance and Stub-based Low-pass Filters for S-Band Applications  ”, BUJICT Journal, Volume 10,  Issue, II December 2017, pp. 1-5.


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