@conference {12_ICEAA_Montejo-GaraiLeal-SevillanoRuiz-CruzEtAl_SymmetricalResponseFilterBartlett, title = {Symmetrical Response Filter Design Applying the Bartlett{\^a}{\texteuro}{\texttrademark}s Theorem and Using Riblet{\^a}{\texteuro}{\texttrademark}s Couplers}, booktitle = {Proc. International Conference on Electromagnetics in Advanced Applications (ICEAA)}, year = {2012}, month = {Sep.}, pages = {1-4}, keywords = {corrugated waveguide, dual-band, mode-matching, optimization, Waveguide polarizers}, author = {Montejo-Garai, J R and C A Leal-Sevillano and J A Ruiz-Cruz and Rebollar, J M} } @conference {11_EuMC_Leal-SevillanoRuiz-CruzMontejo-GaraiEtAl_CADDual-BandPolarizersCorrugatedRectWg, title = {CAD for Dual-Band Polarizers in Corrugated Rectangular Waveguide}, booktitle = {Proc. 41st European Microwave Conference}, year = {2011}, month = {Oct.}, pages = {822-825}, abstract = {Waveguide polarizers are essential devices in feeders for radio transmission systems with circular polarization. In this paper two different dual-band polarizers are designed and compared. The structure of both polarizers is based on the classical corrugated rectangular waveguide. This structure can be analyzed very efficiently like an H-plane and an E-plane problem. The Mode-Matching technique, in combination with global search algorithms, is used for the full-wave analysis and optimization of the polarizers. In the first polarizer, the height of the corrugations is designed according to a taper-type shape. For the second polarizer, no restrictions in the height of the corrugations are imposed and all the dimensions are optimized. The performance of both polarizers is compared, showing certain improvement in terms of polarization purity for the second one.}, keywords = {corrugated waveguide, dual-band, mode-matching, optimization, Waveguide polarizers}, issn = {978-1-61284-235-6}, url = {http://ieeexplore.ieee.org/xpls/abs_all.jsp?arnumber=224789}, author = {C A Leal-Sevillano and J A Ruiz-Cruz and Montejo-Garai, J R and Rebollar, J M} } @conference {11_MULCOPINN_Montejo-GaraiLeal-SevillanoRuiz-CruzEtAl_MultipactorpredictionBandStopFilters, title = {Multipactor prediction in waveguide band-stop filters with wideband spurious-free response}, booktitle = {Proc. International workshop on Multipactor, Corona and Passive Intermodulation (MULCOPIM)}, year = {2011}, month = {Sep.}, pages = {1-6}, keywords = {corrugated waveguide, dual-band, mode-matching, optimization, Waveguide polarizers}, url = {http://mulcopim.webs.upv.es/programme.html}, author = {Montejo-Garai, J R and C A Leal-Sevillano and J A Ruiz-Cruz and Rebollar, J M and Estrada, T} } @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 {08_IJRFMiCAE_Ruiz-CruzMontejo-GaraiRebollar_Full-wavemodelingand, title = {Full-wave modeling and optimization of Boifot junction ortho-mode transducers}, journal = {International Journal of RF and Microwave Computer-Aided Engineering}, volume = {18}, number = {4}, year = {2008}, month = {July}, pages = {303-313}, abstract = {The full-wave design of broadband ortho-mode transducers based on the Boifot junction has two main aspects: an efficient analysis method and a design process divided into tasks with relatively low computational effort. In the analysis part, a rigorous mode-matching technique has been developed to obtain the generalized admittance matrix of the Boifot junction. The other elements of the device are also analyzed by mode-matching. With respect to the design, the proposed procedure starts with the optimization of the individual building blocks of the device. Their interaction is also taken into account in a systematic process. The analysis and design methods have been validated with other numerical methods and an experimental prototype}, keywords = {Boifot ortho-mode transducer, full-wave optimization, generalized admittance matrix, mode-matching}, issn = {1096-4290}, doi = {10.1002/mmce.20287}, url = {http://www3.interscience.wiley.com/cgi-bin/fulltext/119140992/PDFSTART}, author = {J A Ruiz-Cruz and Montejo-Garai, J R and Rebollar, J M} } @article {06_MOTL_Ruiz-CruzMontejo-GaraiRebollarEtAl_Verycompactortho-mode, title = {Very compact ortho-mode transducers with double septum configuration}, journal = {Microwave and Optical Technology Letters}, volume = {48}, number = {4}, year = {2006}, month = {Apr.}, pages = {765-767}, abstract = {This paper describes the analysis and design results of a very compact ortho-mode transducer (OMT) for dual-polarization communication systems. The presented configuration introduces an additional double septum in the conventional structure, not reported previously, which provides a number of advantages for some of the usual requirements of this type of OMTs. Specifically, the double-septum configuration enhances the performance of the OMT in two interrelated aspects: (i) it contributes to reduce the size of the axial branch of the OMT preventing the power transfer between horizontal modes at the axial and common ports; (ii) it facilitates the matching of the horizontal polarization between the lateral and common ports. The presented design leads to a very interesting structure for coping with competitive specifications. The proposed structure is validated using a prototype onboard the Hispasat 1D satellite.}, keywords = {generalized admittance matrix, generalized scattering matrix, mode-matching, ortho-mode, septum}, issn = {0895-2477}, doi = {10.1002/mop.21468}, url = {http://www3.interscience.wiley.com/cgi-bin/fulltext/112467840/PDFSTART}, author = {J A Ruiz-Cruz and Montejo-Garai, J R and Rebollar, J M and Montesano, C E and Mart{\i}n, M J} } @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} }