@article {08_IJRFMiCAE_FahmiRuiz-CruzZaki_EandH-plane,
	title = {E and H-plane wide-band ridge waveguide couplers},
	journal = {International Journal of RF and Microwave Computer-Aided Engineering},
	volume = {18},
	number = {4},
	year = {2008},
	month = {July},
	pages = {348-358},
	abstract = {A systematic synthesis procedure for ridge waveguide branch line couplers in both E-plane and H-plane configurations is presented. Ridge waveguides are chosen to benefit from their wide mono-mode band and compact size compared to rectangular waveguides. Equivalent circuit parameters are used to synthesize the coupler sections. Rigorous mode matching method is used for full-wave analysis and optimization of the couplers. Ridge couplers both in empty waveguide and Low Temperature Co-fired Ceramic "LTCC" technology are designed using the proposed method and the design is verified with another numerical method. A prototype is built and its response is measured to verify the approach},
	keywords = {full-wave, LTCC, mode matching, optimization, ridge waveguide},
	issn = {1096-4290},
	doi = {10.1002/mmce.20293},
	url = {http://www3.interscience.wiley.com/cgi-bin/fulltext/119140987/PDFSTART},
	author = {Fahmi, M M and J A Ruiz-Cruz and Zaki, K A}
}
@conference {07_IMS_Ruiz-CruzZhangRebollarEtAl_TEMMode-MatchingAnalysis,
	title = {TEM Mode-Matching Analysis of Multi-coupled Strip-line Filters},
	booktitle = {2007 IEEE MTT-S International Microwave Symposium Digest},
	year = {2007},
	month = {June},
	pages = {541-544},
	abstract = {The analysis of multi-coupled strip-line filters by the mode-matching method is studied for different input/output excitations. The aim is to compare the computational effort of two different options and to propose the most suitable formulation for the design of some strip-line filters. It is shown that a suitable segmentation of the structure is essential for obtaining good numerical results. In fact, if the optimum segmentation is selected, a mode-matching analysis using only TEM modes can resemble the full-wave response, with shorter computation time. Hence, this approach can be very useful in design and different examples are shown to validate it, using other numerical methods and measurements of a ten order filter.},
	keywords = {microwave filters, mode matching, multicoupled strip-line filter design, optimum structure segmentation, strip line filtersTEM mode-matching analysis},
	issn = {0149-645X},
	doi = {10.1109/MWSYM.2007.380546},
	url = {http://ieeexplore.ieee.org/iel5/4263706/4263707/04263871.pdf?tp=\&isnumber=\&arnumber=4263871},
	author = {J A Ruiz-Cruz and Zhang, Y and Rebollar, J M and Zaki, K A and Montejo-Garai, J R and Piloto, A J}
}
@conference {06_IMS_ZhangRuiz-CruzZaki_RidgeWaveguideDivider,
	title = {Ridge Waveguide Divider Junctions for Wide-Band Multiplexer Applications},
	booktitle = {2006 IEEE MTT-S International Microwave Symposium Digest},
	year = {2006},
	month = {June},
	pages = {1225-1228},
	abstract = {Ridge waveguide divider junctions are introduced and applied to wide-band multiplexer applications. A rigorous analysis and optimization process by mode matching method (MMM) is employed to design the junctions that yield low reflection coefficient in common port and almost equal transmission coefficients in the other two ports over a wide frequency band. Two design examples of wide-band diplexer and triplexer using such junctions are presented. All the components involved in the diplexer/triplexer designs are rigorously modeled and cascaded by MMM. Optimization procedures by MMM are also applied in these two designs to improve the performance. Multiplexers using such junctions can be built in either metallic form or low-temperature co-fired ceramic (LTCC) technology},
	keywords = {low-temperature co-fired ceramics, mode matching, mode matching method, multiplexing equipment, ridge waveguide divider junctions, ridge waveguides, waveguide junctionsLTCC technology, wide-band diplexer, wide-band multiplexer applications, wide-band triplexer},
	issn = {0149-645X},
	doi = {10.1109/MWSYM.2006.249431},
	url = {http://ieeexplore.ieee.org/iel5/4014788/4014789/04015143.pdf?tp=\&isnumber=\&arnumber=4015143},
	author = {Zhang, Y and J A Ruiz-Cruz and Zaki, K A}
}
@conference {06_EuMC_Ruiz-CruzZhangFahmiEtAl_RidgeWaveguideElliptic,
	title = {Ridge Waveguide Elliptic Filters in Narrow-Wall Canonical Configuration},
	booktitle = {Proc. 36th European Microwave Conference},
	year = {2006},
	month = {Sept.},
	pages = {1080-1082},
	abstract = {A new canonical ridge waveguide structure is proposed to design elliptic filter responses. The non-adjacent cavities are coupled by windows situated at the common narrow-wall of the ridge waveguide enclosures. This new configuration provides positive and negative cross couplings using evanescent rectangular waveguides and metallic strips, respectively. The full-wave analysis of the structure is carried out by a rigorous mode matching method. The design is based on circuit synthesis and full-wave optimization. Finally, the proposed structure is elucidated with the design of a four-pole filter and it is validated with the commercial HFSS software},
	keywords = {circuit synthesis, elliptic filters, four-pole filter, full-wave optimization, metallic strips, mode matching, mode matching method, narrow-wall canonical configuration, negative cross couplings, network synthesis, nonadjacent cavities, positive cross couplings, rectangular waveguides, ridge waveguide elliptic filters, ridge waveguides, waveguide filtersHFSS software},
	issn = {2-9600551-6-0},
	doi = {10.1109/EUMC.2006.281121},
	url = {http://ieeexplore.ieee.org/iel5/4057701/4057702/04058011.pdf?tp=\&isnumber=\&arnumber=4058011},
	author = {J A Ruiz-Cruz and Zhang, Y and Fahmi, M M and Zaki, K A}
}
@article {05_IEEETMTT_Ruiz-CruzSabbaghZakiEtAl_Canonicalridgewaveguide,
	title = {Canonical ridge waveguide filters in LTCC or metallic resonators},
	journal = {IEEE Transactions on Microwave Theory and Techniques},
	volume = {53},
	number = {1},
	year = {2005},
	month = {Jan.},
	pages = {174-182},
	abstract = {A new physical realization of an elliptic function filter response is proposed for achieving compact size, wide bandwidth, wide spurious free stopband and high-selectivity performance. The filter configuration can be implemented in conventional waveguide technology or embedded in a multilayer low-temperature co-fired ceramic structure for integration with other circuitry in a chip module. The filter is analyzed using rigorous mode matching. To validate the concept, prototypes of four- and six-cavity elliptic filters are designed following a systematic procedure. Approximate synthesis is used to obtain initial dimensions of the filter and the desired optimum response is obtained by means of a final full-wave optimization. The results are verified with other numerical methods and with the measurements of a fourth-order waveguide filter.},
	keywords = {band-pass filters, canonical ridge waveguide filters, cavity resonator filters, ceramics, chip module, circuit optimisation, elliptic filters, elliptic function filter response, four cavity elliptic filters design, fourth order waveguide filter, full-wave optimization, metallic resonators, microwave filters, mode matching, multilayer low temperature cofired ceramic structure, multilayers, numerical methods, prototypes, resonators, ridge waveguides, six cavity elliptic filters design, spurious free stopband filter, waveguide filters band pass filters, waveguide technology},
	issn = {0018-9480},
	doi = {10.1109/TMTT.2004.839324},
	url = {http://ieeexplore.ieee.org/iel5/22/30125/01381687.pdf?tp=\&arnumber=1381687\&isnumber=30125},
	author = {J A Ruiz-Cruz and El Sabbagh, M A and Zaki, K A and Rebollar, J M and Zhang, Y}
}
@conference {05_IMS_FahmiRuiz-CruzZakiEtAl_LTCCwide-bandcanonical,
	title = {LTCC wide-band canonical ridge waveguide filters},
	booktitle = {2005 IEEE MTT-S International Microwave Symposium Digest},
	year = {2005},
	month = {June},
	pages = {249-252},
	abstract = {A canonical LTCC ridge waveguide filter for wide-band application is proposed. A new coupling scheme is employed to achieve the values of the cross couplings needed to increase the bandwidth. The change of the realization of the coupling sections from rectangular to narrow ridge waveguide is shown to eliminate detrimental undesired cross coupling. To validate the concept, rigorous mode matching method is used for full-wave analysis and optimization of a six pole filter. The response is verified with another numerical method, and a prototype is constructed for testing.},
	keywords = {canonical ridge waveguide filters, ceramic packaging, coupling scheme, coupling sections, full-wave analysis, mode matching, mode matching method, narrow ridge waveguide, optimisation, ridge waveguides, six pole filter, waveguide filters LTCC, wide-band filters},
	issn = {01490-645X},
	doi = {10.1109/MWSYM.2005.1516572},
	url = {http://ieeexplore.ieee.org/iel5/10171/32491/01516572.pdf?tp=\&isnumber=\&arnumber=1516572},
	author = {Fahmi, M M and J A Ruiz-Cruz and Zaki, K A and Piloto, A J}
}
@conference {05_IMS_Ruiz-CruzZakiMontejo-GaraiEtAl_Rectangularwaveguideelliptic,
	title = {Rectangular waveguide elliptic filters with capacitive and inductive irises and integrated coaxial excitation},
	booktitle = {2005 IEEE MTT-S International Microwave Symposium Digest},
	year = {2005},
	month = {June},
	pages = {269-272},
	abstract = {CAD of rectangular waveguide filters with elliptic responses is described. The configuration uses capacitive and inductive irises in order to achieve the different coupling signs required to synthesize finite transmission zeros in the rejection bands. The input and output ports are realized by a coaxial probe that directly excites the input/output cavities. The analysis is done by the efficient mode-matching method, in order to allow a final full-wave optimization taking into account all the higher order mode interactions. The CAD results are verified with the HFSS and a filter was manufactured for testing.},
	keywords = {band-stop filters, capacitive iris, circuit CAD, coaxial probe, coaxial waveguides, elliptic filters, finite transmission zeros, full-wave optimization, higher order mode interactions, inductive iris, input ports, integrated coaxial excitation, mode matching, mode-matching method, optimisation, output ports, rectangular waveguide filter, rectangular waveguides, rejection bands, waveguide filters CAD},
	issn = {01490-645X},
	doi = {10.1109/MWSYM.2005.1516577},
	url = {http://ieeexplore.ieee.org/iel5/10171/32491/01516577.pdf?tp=\&isnumber=\&arnumber=1516577},
	author = {J A Ruiz-Cruz and Zaki, K A and Montejo-Garai, J R and Rebollar, J M}
}
@conference {05_IMS_Ruiz-CruzZhangZakiEtAl_Ridgewaveguidebranch-line,
	title = {Ridge waveguide branch-line directional couplers for wideband applications and LTCC technology},
	booktitle = {2005 IEEE MTT-S International Microwave Symposium Digest},
	year = {2005},
	month = {June},
	pages = {1219-1222},
	abstract = {A new branch-line directional coupler is proposed for achieving wide bandwidth. The device is implemented in ridge waveguide to exploit its wide monomode band. It can be physically realized either in empty ridge waveguide or in LTCC for integration in a chip module. Two prototypes of two and five branches are designed following a systematic procedure. An appropriate equivalent circuit provides initial dimensions and the desired optimum response is obtained by means of a final full-wave optimization based on the rigorous and efficient mode-matching method. The results are verified with the finite element method of the HFSS software and a prototype will be manufactured for testing},
	keywords = {branch-line directional couplers, chip module integration, directional couplers, equivalent circuits, finite element analysis, finite element method, full-wave optimization, mode matching, mode-matching method, optimisation, ridge waveguides, ridge waveguidesLTCC technology, wide monomode band},
	issn = {01490-645X},
	doi = {10.1109/MWSYM.2005.1516896},
	url = {http://ieeexplore.ieee.org/iel5/10171/32491/01516896.pdf?tp=\&isnumber=\&arnumber=1516896},
	author = {J A Ruiz-Cruz and Zhang, Y and Zaki, K A and Piloto, A J and Rebollar, J M}
}
@conference {04_IMS_LiuRuiz-CruzWangEtAl_extremelywidebandridge,
	title = {An extremely wideband ridge waveguide filter},
	booktitle = {2004 IEEE MTT-S International Microwave Symposium Digest},
	volume = {2},
	year = {2004},
	month = {June},
	pages = {615-618},
	abstract = {An extremely wideband ridge waveguide filter is presented. The fractional bandwidth of the filter can be greater than 115\%. An input and output transition from ridge waveguide to stripline and then to coax is also designed. The analysis is done with mode matching method and verified with Ansoft HFSS. For validation purpose, a test filter with pass band from 3 GHz to 9 GHz has been designed. The results by both mode matching method and Ansoft HFSS are presented. Excellent agreement is obtained. The test filter is designed using air filled ridge waveguide; however the same design procedure can be equally applied to other manufacturing techniques such as LTCC.},
	keywords = {air filled ridge waveguide, fractional bandwidth, mode matching, mode matching method, ridge waveguides, strip lines, stripline, waveguide filters 3 to 9 GHz, wideband ridge waveguide filter},
	issn = {0149-645X},
	doi = {10.1109/MWSYM.2004.1336059},
	url = {http://ieeexplore.ieee.org/iel5/9277/29472/01336059.pdf?tp=\&isnumber=\&arnumber=1336059},
	author = {Liu, Z M and J A Ruiz-Cruz and Wang,C and Zaki, K A}
}
@conference {04_IMS_Ruiz-CruzElZakiEtAl_Full-wavedesignof,
	title = {Full-wave design of canonical ridge waveguide filters},
	booktitle = {2004 IEEE MTT-S International Microwave Symposium Digest},
	volume = {2},
	year = {2004},
	month = {June},
	pages = {603-606},
	abstract = {A new physical realization of an elliptic function filter response is proposed for achieving compact size, wide bandwidth, wide spurious free stop band and high selectivity performance. The canonical ridge waveguide filter configuration is analyzed using rigorous mode-matching. To validate the concept, a prototype that realizes the coupling matrix of a canonical four cavity elliptic filter is designed following a systematic procedure. Approximate synthesis is used to obtain initial dimensions of the filter and the desired optimum response is obtained by means of a final full-wave optimization. The results are verified with other numerical method and a prototype will be built for testing.},
	keywords = {band-pass filters, coupling matrix, elliptic filters, elliptic function filter, filtering theory, full-wave design, full-wave optimization, mode matching, mode-matching, waveguide filters canonical ridge waveguide filters, wide bandwidth, wide spurious free stop band},
	issn = {0149-645X},
	doi = {10.1109/MWSYM.2004.1336056},
	url = {http://ieeexplore.ieee.org/iel5/9277/29472/01336056.pdf?tp=\&isnumber=\&arnumber=1336056},
	author = {J A Ruiz-Cruz and El Sabbagh, M A and Zaki, K A and Rebollar, J M}
}
@conference {04_APS_Ruiz-CruzZakiRebollar_Mode-matchinganalysisof,
	title = {Mode-matching analysis of a coaxial-to-stripline discontinuity applied to the modeling of a coaxial probe},
	booktitle = {Proc. 2004 IEEE Antennas and Propagation Society International Symposium},
	volume = {2},
	year = {2004},
	month = {June},
	pages = {2139-2142},
	abstract = {The paper presents the analysis of the discontinuity between a coaxial and a generalized stripline waveguide and its application to the characterization of a probe inside a rectangular waveguide. The probe is modeled by a stripline whose inner conductor is stepped. For thin probes, just a reduced number of sections is needed and its characterization can be obtained very efficiently. The mode-matching technique is employed for analyzing the basic discontinuity, and the inner cross products between the modes are computed by means of the Bessel-Fourier series, reducing the computation time with respect to a pure numerical integration. The simulation results are compared with those obtained by other numerical techniques.},
	keywords = {coaxial probe modeling, coaxial waveguide, coaxial waveguides, coaxial-to-stripline discontinuity, computation time, Fourier series, mode matching, mode-matching analysis, numerical integration, rectangular waveguide, strip line discontinuities Bessel-Fourier series, stripline waveguide},
	issn = {0-7803-8302-8},
	doi = {10.1109/APS.2004.1330633},
	url = {http://ieeexplore.ieee.org/iel5/9253/29356/01330633.pdf?tp=\&isnumber=\&arnumber=1330633},
	author = {J A Ruiz-Cruz and Zaki, K A and Rebollar, J M}
}
