@article {Naghar20151813, title = {Design of compact multiband bandpass filter with suppression of second harmonic spurious by coupling gap reduction}, journal = {Journal of Electromagnetic Waves and Applications}, volume = {29}, number = {14}, year = {2015}, note = {cited By 1}, pages = {1813-1828}, abstract = {In this paper, we describe a method to implement compact multiband bandpass filters with suppression of second harmonic frequency. This filter design approach is based on decreasing the coupling gap between adjacent resonators of a parallel-coupled-line bandpass filter in order to achieve both the desired multiband frequency response and the spurious suppression. We present the theoretical analysis of the proposed structure that consists of modeling the frequency dependence of the even- and odd-mode characteristic impedances as well as due to the different phase velocities of the parallel-coupled microstrip lines. As an example, a compact tri-band parallel-coupled-line bandpass filter with suppression of second harmonic frequency was implemented operating at 1.9/3.2/4.6 GHz to cover PCS1900, WiMAX, and C-band applications. A three-pole Chebyshev parallel-coupled microstrip bandpass filter was designed at a center frequency of 3.2 GHz and used as the basis to validate the gapping effect on the filter response which also achieves a narrower bandwidth for the second harmonic. Finally, the filter performance with minimized coupling gap is compared to a filter enhanced by the insertion of apertures in the ground plane. Generally speaking, good agreement was accomplished between simulated, calculated, and measured results. {\textcopyright} 2015 Taylor \& Francis.}, doi = {10.1080/09205071.2015.1043029}, url = {https://www.scopus.com/inward/record.uri?eid=2-s2.0-84940714115\&doi=10.1080\%2f09205071.2015.1043029\&partnerID=40\&md5=b402327d69e8f5f98418025a5c5cd607}, author = {Naghar, A.a and Aghzout, O.a and Alejos, A.V.b and Sanchez, M.G.b and Essaaidi, M.c} } @conference {Naghar20142018, title = {Development of a calculator for Edge and Parallel Coupled Microstrip band pass filters}, booktitle = {IEEE Antennas and Propagation Society, AP-S International Symposium (Digest)}, year = {2014}, note = {cited By 3}, pages = {2018-2019}, abstract = {This paper presents an implemented calculator tool for the design of Edge/ Parallel Coupled Microstrip Band Pass Filters (PCMBPF) that makes use of the MATLAB software. This calculator allows estimating both the parameters required for the design of the PCMBPF and the electrical response which is obtained by means of the equivalent circuit of this type of filters. Based on the transmission line theory approach (TLTA), the calculator herein proposed is a good solution to simply obtain the design parameters of this type of filters given that all formulas required for the PCMBPF design are programmed using close-form mathematic expressions and the coupling matrix concept. In order to validate our calculator performance, we implemented the proposed filter in a commercial electromagnetic simulator CST MWs that considers a set of electromagnetic effects, and accurately determine the final filter design. Secondly, we compared these simulation outcomes with the measurement results, achieving a reasonable agreement. {\textcopyright} 2014 IEEE.}, doi = {10.1109/APS.2014.6905336}, url = {https://www.scopus.com/inward/record.uri?eid=2-s2.0-84907870530\&doi=10.1109\%2fAPS.2014.6905336\&partnerID=40\&md5=bc3cd87613500ca710b9f58fdca9f27d}, author = {Naghar, A.a and Aghzout, O.a and Vazquez Alejos, A.b and Garcia Sanchez, M.b and Essaaidi, M.c} }