@article {12_IEEEMWCL_Leal-SevillanoMontejo-GaraiRuiz-CruzEtAl_Low-LossEllipticalResponse, title = {Low-Loss Elliptical Response Filter at 100 GHz}, journal = {Microwave and Wireless Components Letters, IEEE}, volume = {22}, number = {9}, year = {2012}, month = {September}, pages = {459 -461}, abstract = {The design, method of fabrication and experimental validation of a pseudo-elliptical four-poles asymmetric response filter at 100 GHz with 10\% of fractional bandwidth is presented. The designed filter is part of an image radar system and must fulfill stringent specifications. The proposed topology and method of fabrication improves the out of band rejection above the pass band in comparison with other classical structures, while keeping a low insertion loss level. A two-fold geometry for implementing a transmission zero is proposed, avoiding the excitation of the first higher order mode and easing the manufacturing without any tuning element. A low-cost milling process is used for the fabrication of the device. The final design fulfills the desired specifications and presents 0.6 dB of insertion loss level at 100 GHz. The excellent agreement between simulations and measurements at this frequency band in both, return loss and insertion loss, is pointed out.}, keywords = {Asymmetric, band-pass filters, elliptic filters, extracted pole, Fabrication, fabrication method, filter, filtering theory, fractional bandwidth, frequency 100 GHz, higher order mode, image radar system, Insertion loss, loss 0.6 dB, Loss measurement, low insertion loss level, low loss, low-cost milling process, low-loss elliptical response filter, microwave filters, millimetre wave filters, Milling, out of band rejection, pseudo-elliptical four-poles asymmetric response filter, Radar, return loss, transmission zero, two-fold geometry, W-band}, issn = {1531-1309}, doi = {10.1109/LMWC.2012.2212237}, url = {http://ieeexplore.ieee.org/xpls/abs_all.jsp?arnumber=6268297\&tag=1}, author = {C A Leal-Sevillano and Montejo-Garai, J R and J A Ruiz-Cruz and Rebollar, J M} } @conference {07_IMS_ZhangZakiRuiz-CruzEtAl_AnalyticalSynthesisof, title = {Analytical Synthesis of Generalized Multi-band Microwave Filters}, booktitle = {2007 IEEE MTT-S International Microwave Symposium Digest}, year = {2007}, month = {June}, pages = {1273-1276}, abstract = {An analytical procedure is presented for the synthesis of generalized multi-band filters. The procedure is applicable to both symmetric and asymmetric frequency responses and effective for any number of passbands and stopbands. An optimum equal-ripple performance is obtained in each passband and stopband. Prescribed real or complex transmission zeros can also be employed in the multi-band filtering function.}, keywords = {band-pass filters, band-stop filters, generalized multiband microwave filters, microwave filtersfrequency responses, optimum equal-ripple performance, passbands, stopbands}, issn = {0149-645X}, doi = {10.1109/MWSYM.2007.380425}, url = {http://ieeexplore.ieee.org/iel5/4263706/4263707/04264064.pdf?tp=\&isnumber=\&arnumber=4264064}, author = {Zhang, Y and Zaki, K A and J A Ruiz-Cruz and Atia, A E} } @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} } @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_APS_ZhangZakiRuiz-Cruz_Dualmodebandpass, title = {Dual mode bandpass filter with asymmetric transfer function}, booktitle = {Proc. 2005 IEEE Antennas and Propagation Society International Symposium}, volume = {2B}, year = {2005}, month = {July}, pages = {634-637}, abstract = {We demonstrate the feasibility of dual mode implementation of an asymmetric elliptic filter. A filter which has four poles and one transmission zero is synthesized from the general Chebyshev transfer function. The ideal electrical network of the longitudinal form is then obtained through several "rotation" operations on the initial coupling matrix. Finally, the dual mode circular waveguides are adopted to realize the ideal network.}, keywords = {asymmetric elliptic filter, asymmetric transfer function, band-pass filters, Chebyshev filters, circular waveguides, coupling matrix, dual mode bandpass filter, dual mode circular waveguides, elliptic filters, ideal network, microwave filters, poles, poles and zeros, rotation operations, transfer function matrices, transmission zero, waveguide filters Chebyshev transfer function}, issn = {0-7803-8884-4}, doi = {10.1109/APS.2005.1552092}, url = {http://ieeexplore.ieee.org/iel5/10402/33057/01552092.pdf?tp=\&isnumber=\&arnumber=1552092}, author = {Zhang, Y and Zaki, K A and J A Ruiz-Cruz} } @article {05_IEEETMTT_Montejo-GaraiRuiz-CruzRebollarEtAl_Synthesisanddesign, title = {Synthesis and design of in-line N-order filters with N real transmission zeros by means of extracted poles implemented in low-cost rectangular H-plane waveguide}, journal = {IEEE Transactions on Microwave Theory and Techniques}, volume = {53}, number = {5}, year = {2005}, month = {May}, pages = {1636-1642}, abstract = {In this paper, an extension to the extracted pole technique for synthesizing N-order filters with N-transmission zeros at real frequencies is presented. In addition, a new bandpass rectangular waveguide H-plane low-cost configuration filter for high-power low-loss application (patent pending) that implements a filtering function with finite real frequency transmission zeros is proposed. This structure operates as a resonant cavity in transmission at central frequency of the bandpass and simultaneously introduces a controlled transmission zero out of the bandpass. Since every double-controlled electrical behavior cavity introduces a transmission zero, it is possible to introduce as many transmission zeros as the order of the filtering function. In order to validate the synthesis procedure and the new structure, different filters have been designed: a second-order filter with two transmission zeros, a third-order filter with one transmission zero, a fourth-order filter with two transmission zeros, and finally, an eighth-order filter with two transmission zeros. The last two have been manufactured, showing an excellent agreement between the measurement and theoretical simulation.}, keywords = {band-pass filters, double-controlled electrical behavior cavity, eighth-order filter, extracted pole technique, filter synthesis, filtering function, finite real frequency transmission zeros, fourth-order filter, in-line N-order filters, network synthesis, planar waveguides, poles and zeros, rectangular H-plane waveguide, rectangular waveguides, resonant cavity, second-order filter, third-order filter, waveguide filters bandpass rectangular waveguide H-plane filter}, issn = {0018-9480}, doi = {10.1109/TMTT.2005.847053}, url = {http://ieeexplore.ieee.org/iel5/22/30829/01427966.pdf?tp=\&isnumber=\&arnumber=1427966}, author = {Montejo-Garai, J R and J A Ruiz-Cruz and Rebollar, J M and Padilla-Cruz, M J and Onoro-Navarro,A and Hidalgo-Carpintero, I} } @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 {02_APS_Ruiz-CruzMontejo-GaraiRebollar_Characterisationofwaveguide, title = {Characterisation of waveguide discontinuities with finite wall conductivity}, booktitle = {Proc. 2002 IEEE Antennas and Propagation Society International Symposium}, volume = {4}, year = {2002}, month = {June}, pages = {428-431}, abstract = {In this paper, a procedure is proposed to evaluate the generalised scattering matrix of waveguide discontinuities with finite wall conductivity. This approach is applied to evaluate the insertion losses in several waveguide structures of Chebyshev bandpass filters. These numerical results are compared with those obtained with other numerical methods and with measurements, validating the proposed procedure.}, keywords = {band-pass filters, Chebyshev filters, electromagnetic wave scattering, finite wall conductivity, generalised scattering matrix, insertion losses, numerical methods, S-matrix theory, waveguide discontinuities, waveguide filters, waveguide theory Chebyshev bandpass filters}, issn = {0-7803-7330-8}, doi = {10.1109/APS.2002.1017013}, url = {http://ieeexplore.ieee.org/iel5/7931/21884/01017013.pdf?tp=\&isnumber=\&arnumber=1017013}, author = {J A Ruiz-Cruz and Montejo-Garai, J R and Rebollar, J M} }