Tuning the Resonance Frequency and Miniaturization of a Novel Microstrip Bandpass Filter

Abbas Rezaei, Leila Noori


In this paper, a compact microstrip bandpass filter is designed using two open loop resonators. In order to obtain a tunable bandpass response with low insertion loss, two stubs are loaded inside them. The design process is based on obtaining the input admittance. Then, using the input admittance, a method is presented to control the resonance frequency and miniaturization simultaneously. The obtained insertion loss and the return loss at the resonance frequency are 0.1 dB and 19.7 dB respectively. To verify the design method, the proposed filter is fabricated and measured. The measured results are in good agreement with the simulated results.


Microstrip filter; Tunable; Miniaturization; Insertion loss.

Full Text:



Chen WL, Wang GM (2009), Effective design of novel compact fractal-shaped microstrip coupled-line bandpass filters for suppression of the second harmonic. IEEE Microwave and Wireless Components Letters 19(25): 74-76.

Deng PH, Chiu PT (2010), New bandpass filters using half-wavelength and branch-line resonators. Progress In Electromagnetics Research, 16: 241-249.

Fathelbab WM, Steer MB (2005), Parallel-coupled line filters with enhanced stopband performances. IEEE Transactions on Microwave Theory and Techniques 53(12): 3774-3781.

Guan X, Gui P, Xiong T, Ren B, Zhu L (2017), Hybrid microstrip/slotline ultra-wideband bandpass filter with a controllable notch band. International Journal of Antennas and Propagation 2017: 1-7.

Li YC, Zhang XY, Xue Q (2010), Bandpass filter using discriminating coupling for extended out-of-band suppression. IEEE Microwave and Wireless Components Letters 20 (7): 369-371.

Moradian M, Tayarani M (2009), Improving the stopband of microstrip parallel-coupled line bandpass filters using partially coupled resonators. IET Microwaves, Antennas and Propagation 4(7): 906-916.

Othman MA, Sinnappa M, Hussain MN, Abd MZA, Ismail MM (2013), Development of 5.8 GHz microstrip parallel coupled line bandpass filter for wireless communication system. International Journal of Engineering and Technology 5(4): 3227-3235.

Salehi MR, Abiri E, Noori L (2014), Design of a microstrip dual-band bandpass filter with compact size and tunable resonance frequency for WLAN application. International Journal of Electronics Communication and Computer Engineering 6(3): 248-251.

Wang Y, Wang BZ, Wang J (2008), The design of coupled resonator bandpass filter with wide stop-band. IEEE Microwave and Wireless Components Letters 18(4): 251-253.

Wu XH, Wei XB, Lv HG, Shi Y (2017), A compact trisection microstrip bandpass filter with frequency-dependent cross-coupling. Electromagnetics 37(7): 454-461.

Zhang XY, Xue Q (2009), Harmonic-suppressed bandpass filter based on discriminating coupling. IEEE Microwave and Wireless Components Letters 19(11): 695-697.

DOI: http://dx.doi.org/10.24200/tjer.vol15iss2pp24-28


  • There are currently no refbacks.

Copyright (c) 2018 Abbas Rezaei, Leila Noori

Creative Commons License
This work is licensed under a Creative Commons Attribution-NoDerivatives 4.0 International License.


This journal and its content is licensed under a Attribution-NoDerivatives 4.0 International.

Flag Counter