@article {09_IEEETMTT_FahmiRuiz-CruzMansourEtAl_CompactRidgeWaveguideTZNRN,
	title = {Compact Ridge Waveguide Filters With Arbitrarily Placed Transmission Zeros Using Nonresonating Nodes},
	journal = {IEEE Transactions on Microwave Theory and Techniques},
	volume = {57},
	number = {12},
	year = {2009},
	month = {Dec.},
	pages = {3354-3361},
	abstract = {Compact size ridge waveguide filters based on the nonresonating node concept are introduced to realize transfer functions with arbitrarily placed attenuation poles. Coupling mechanisms, suitable for the new realization are introduced in diverse $E$ -plane and $H$ -plane configurations and with different input-output interfaces. These coupling structures are studied and characterized in detail in order to simplify the design of the proposed filters. Rigorous mode-matching method is used to accelerate the full-wave design of the filter configurations, whose response is also verified using other numerical techniques and experimental data. To validate the proposed novel designs, a prototype has been built and tested. Measurement results agree well with the predicted theoretical simulations.},
	keywords = {Attenuation poles, microwave filters, mode-matching, ridge waveguides},
	issn = {0018-9480},
	doi = {10.1109/TMTT.2009.2034423},
	url = {http://ieeexplore.ieee.org/stamp/stamp.jsp?tp=\&arnumber=5308444\&isnumber=5340253},
	author = {Fahmi, M M and J A Ruiz-Cruz and Mansour, R R and Zaki, K A}
}
@article {07_IEEEMWCL_Ruiz-CruzZhangZakiEtAl_Ultra-WidebandLTCCRidge,
	title = {Ultra-Wideband LTCC Ridge Waveguide Filters},
	journal = {IEEE Microwave and Wireless Components Letters},
	volume = {17},
	number = {2},
	year = {2007},
	month = {Feb.},
	pages = {115-117},
	abstract = {The design and experimental validation of an ultra-wideband (UWB) filter in a low temperature co-fired ceramic (LTCC) is presented. The bandpass filter uses ridge waveguide resonators realized in LTCC by printing parallel planar conductors for the top and bottom walls and closely spaced metal filled vias for the lateral walls. Filter coupling scheme and stripline transitions are developed for the UWB requirement. The mode-matching method is used in their design. The LTCC via effect and the measurement setup are also addressed. Finally, experimental results of a nine-order filter (design passband from 3 to 9GHz) are presented},
	keywords = {band-pass filters, bandpass filter, filter coupling scheme, low temperature co fired ceramic, LTCC, metal filled vias, mode matching method, nine order filter, planar conductors, ridge waveguide filters, ridge waveguide resonators, ridge waveguides, stripline transitions, ultra wideband filter, waveguide filters3 to 9 GHz},
	issn = {1531-1309},
	doi = {10.1109/LMWC.2006.890333},
	url = {http://ieeexplore.ieee.org/iel5/7260/4079621/04079639.pdf?tp=\&isnumber=4079621\&arnumber=4079639\&punumber=7260},
	author = {J A Ruiz-Cruz and Zhang, Y and Zaki, K A and Piloto, A J and Tallo, 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-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}
}
