Journal of Communication Engineering

Journal of Communication Engineering

High performance Lowpass Filter using Tetramerous Radial Stubs

Document Type : Research Paper

Authors
Salma Ali Sadeq 1
Mohsen Hayati 2
Hamed Abbasi 3
Sajjad Mohanad Mustafa 2
Farzin Shama 3
1 Department of Electronic and Communication Engineering, Faculty of Engineering, University of Kufa, Kufa Street, Najaf 54001, Iraq.
2 Razi University, Faculty of Engineering, Department of Electrical Engineering, Tagh-E-Bostan Kermanshah, 6714414971, Iran.
3 Department of Electrical Engineering, Ker.C., Islamic Azad University, Kermanshah, Iran.
10.22070/jce.2025.19485.1275
Abstract
This paper introduces a novel microstrip lowpass filter characterized by several remarkable features, including a sharp roll-off, extensive stopband, minimal insertion loss, compact dimensions, and high return loss, all achieved through the innovative use of tetramerous radial stub resonators. The transition band of the filter spans approximately 0.31 GHz, ranging from 1.96 to 2.27 GHz, with notable attenuation levels of −3 dB and −40 dB at the respective edges. Additionally, the stopband extends impressively from 2.2 GHz to 22 GHz, achieving attenuation greater than 20 dB, which ensures effective signal suppression outside the desired frequency range. In the passband, the insertion loss is exceptionally low, remaining below 0.1 dB, while the return loss exceeds 19.89 dB, indicating excellent matching characteristics. Furthermore, the total area of the filter measures a compact 189 mm², making it suitable for space-constrained applications. The proposed design has been fabricated and tested, with results from simulations and measurements demonstrating strong correlation and validating its performance.
Keywords
low insertion loss
lowpass filter
tetramerous radial stubs resonator
ultra wide stopband
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