@article { ISI:000360305800001,
	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},
	month = {SEP 22},
	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 1.9/3.2/4.6GHz to cover PCS1900, WiMAX, and C-band applications. A three-pole Chebyshev parallel-coupled microstrip bandpass filter was designed at a center frequency of 3.2GHz 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.},
	issn = {0920-5071},
	doi = {10.1080/09205071.2015.1043029},
	author = {Naghar, Azzedin and Aghzout, Otman and Vazquez Alejos, Ana and Garcia Sanchez, Manuel and Essaaidi, Mohammed}
}
@article { ISI:000366391200018,
	title = {Design of compact wideband multi-band and ultrawideband band pass filters based on coupled half wave resonators with reduced coupling gap},
	journal = {IET MICROWAVES ANTENNAS \& PROPAGATION},
	volume = {9},
	number = {15},
	year = {2015},
	month = {DEC 10},
	pages = {1786-1792},
	abstract = {In this paper we propose a technique to design compact multi-band and UWB bandpass filters based on coupled half wave resonators. The proposed design consists of the modification of a conventional parallel coupled Chebyshev bandpass filter structure by setting a very small or null coupling gap between the resonators of the center sections jointly with a very small spacing between resonators of the extremity sections. This spacing determines the performances of selected frequency bands. An ultrawideband response is accomplished by applying null spacing between all the adjacent resonators. We analysed the effect of the separation distance between the coupled lines on both the fractional bandwidth and group velocity of the filter response. The effect of the order assumed for the initial Chebyshev filter was also discussed. As an illustration of the proposed technique, we designed and measured a dual band and a tri-band filter for the frequencies covering the WiMAX/WLAN/X system bands demonstrating an excellent performance, with a fractional bandwidth covering the 40\% and 100\% of the FCC bandwidth respectively. The proposed technique alleviates the fabrication accuracy requirements. The designs show an optimal improvement in terms of group velocity flatness.},
	issn = {1751-8725},
	doi = {10.1049/iet-map.2015.0188},
	author = {Naghar, Azzedin and Aghzout, Otman and Vazquez Alejos, Ana and Garcia Sanchez, Manuel and Essaaidi, Mohamed}
}
@article {11164386420151201,
	title = {Design of compact wideband multi-band and ultrawideband band pass filters based on coupled half wave resonators with reduced coupling gap.},
	journal = {IET Microwaves, Antennas \& Propagation},
	volume = {9},
	number = {15},
	year = {2015},
	pages = {1786 - 1792},
	abstract = {In this paper we propose a technique to design compact multi-band and UWB bandpass filters based on coupled half wave resonators. The proposed design consists of the modification of a conventional parallel coupled Chebyshev bandpass filter structure by setting a very small or null coupling gap between the resonators of the center sections jointly with a very small spacing between resonators of the extremity sections. This spacing determines the performances of selected frequency bands. An ultrawideband response is accomplished by applying null spacing between all the adjacent resonators. We analysed the effect of the separation distance between the coupled lines on both the fractional bandwidth and group velocity of the filter response. The effect of the order assumed for the initial Chebyshev filter was also discussed. As an illustration of the proposed technique, we designed and measured a dual band and a tri-band filter for the frequencies covering the WiMAX/WLAN/X system bands dem},
	keywords = {Bandpass filters {\textendash} Research, Chebyshev systems {\textendash} Research, Electric resonators {\textendash} Research, Ultra-wideband antennas {\textendash} Research, Wireless LANs {\textendash} Research},
	issn = {17518725},
	url = {http://search.ebscohost.com/login.aspx?direct=true\&db=iih\&AN=111643864\&site=ehost-live},
	author = {Naghar, Azzedin and Aghzout, Otman and Vazquez Alejos, Ana and Garcia Sanchez, Manuel and Essaaidi, Mohamed}
}
@conference { ISI:000361554402054,
	title = {Development of a Calculator for Edge and Parallel Coupled Microstrip Band Pass Filters},
	booktitle = {2014 IEEE ANTENNAS AND PROPAGATION SOCIETY INTERNATIONAL SYMPOSIUM (APSURSI)},
	series = {IEEE Antennas and Propagation Society International Symposium},
	year = {2014},
	note = {IEEE Antennas-and-Propagation-Society International Symposium (APSURSI), Memphis, TN, JUL 06-11, 2014},
	pages = {2018-2019},
	publisher = {Inst Elect Elect Engineers; Inst Elect Elect Engineers Antennas \& Propagat Soc},
	organization = {Inst Elect Elect Engineers; Inst Elect Elect Engineers Antennas \& Propagat Soc},
	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 MA TLAB 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.},
	isbn = {978-1-4799-3540-6},
	issn = {1522-3965},
	author = {Naghar, Azzeddin and Aghzout, Otman and Vazquez Alejos, Ana and Garcia Sanchez, Manuel and Essaaidi, Mohamed}
}
