@article {10_IEEEMWCL_ZhangRuiz-CruzZaki_WaveguideMicrostripTransition, title = {A Waveguide to Microstrip Inline Transition With Very Simple Modular Assembly}, journal = {IEEE Microwave and Wireless Components Letters}, volume = {20}, number = {9}, year = {2010}, month = {Sept.}, pages = {480-482}, abstract = {A microstrip to empty rectangular waveguide transition is presented for systems requiring a simple modular assembly with good electrical performance. The structure is based on three building blocks, involving a microstrip line to dielectric-loaded rectangular waveguide, a transition between dielectric-loaded and empty rectangular waveguides with reduced height, and a final transformer to standard waveguide. These three building blocks (segmentation based on the design point of view) are combined in three simple parts which are assembled in a straightforward modular way, without soldering. These features are very important for signal feeders requiring a large number of transitions, as the X-band phased array antenna where the proposed structure has been integrated. The concepts involved in the design and manufacturing are illustrated with a prototype showing measured return loss of 10 dB and insertion loss of 1.1 dB in the band 8.5-9.5 GHz.}, issn = {1531-1309}, doi = {10.1109/LMWC.2010.2056358}, url = {http://ieeexplore.ieee.org/xpl/freeabs_all.jsp?arnumber=5545481}, author = {Zhang, Y and J A Ruiz-Cruz and Zaki, K A and Piloto, A J} } @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} } @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 {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} }