@article {13_IETMAP_Montejo-GaraiRuiz-CruzLeal-SevillanoEtAl_ModelingofDual-PolarizationDiplexers, title = {Modeling of Dual-Polarization Diplexers Based on Enhanced Multiport Turnstile Junctions}, journal = {IET Microwaves, Antennas and Propagation}, volume = {7}, number = {7}, year = {2013}, month = {May}, pages = {485-492}, abstract = {The modelling of waveguide diplexers working simultaneously with two dual-polarisation signals is presented in this study. The proposed network is an ortho-mode junction with six physical ports based on an enhanced multiport turnstile junction. This structure is excited at the common port coming from the antenna, by two signals at different frequency bands which are required to be discriminated into dedicated ports. The added functionality of the structure presented in this work is that each frequency band can also allocate two orthogonal polarisations (dual linear or dual circular) with a very large separation between bands (fractional bandwidth larger than 55\%), using two different waveguiding concepts. The first one is based on confining the high frequencies at the centre of the axial path. The second one is just the dual, diverting the high frequencies to the outer boundaries of the axial path. The proposed structures, whose modelling and design will be addressed, are suited for low insertion loss and high-power applications, since they do not use metallic pins, irises or small waveguide sections. Moreover, as consequence of the introduced waveguiding concepts, they are very compact and short in the axial direction, which is crucial for this type of feeders in satellite applications.}, keywords = {antenna feeds, multifrequency antennas, multiplexing equipment, multiport networks, waveguide junctions}, issn = {1751-8725}, doi = {10.1049/iet-map.2012.0424}, url = {http://ieeexplore.ieee.org/stamp/stamp.jsp?tp=\&arnumber=6552358}, author = {Montejo-Garai, J R and J A Ruiz-Cruz and C A Leal-Sevillano and Rebollar, J M} } @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 {05_EuMC_Montejo-GaraiRuiz-CruzRebollar_Synthesisanddesign, title = {Synthesis and design of a manifold triplexer implemented in a three layer rectangular H-plane waveguide}, booktitle = {Proc. 35th European Microwave Conference}, volume = {1}, year = {2005}, month = {Oct.}, pages = {1-4}, abstract = {In this article, a new procedure for the design and construction of a contiguous band manifold triplexer in H-plane configuration is presented. Such a configuration eliminates the slots between the T-junctions and the filters allowing high power handling as well as reducing dramatically the risk of multipactor. In addition, the device has been manufactured using a three layer sandwich configuration. In this way, the classical milling machine has been replaced by a wire-electric-milling one. The rounded corners are removed and consequently the tuning process is practically eliminated. In order to validate the above performance, a Ku-band triplexer has been designed, manufactured and measured.}, keywords = {contiguous band manifold triplexer, microwave devices, multiplexing equipment, rectangular waveguides, slot lines Ku-band triplexer, three layer rectangular H-plane waveguide, three layer sandwich configuration, wire-electric-milling machine}, issn = {2-9600551-2-8}, doi = {10.1109/EUMC.2005.1608801}, url = {http://ieeexplore.ieee.org/iel5/10686/33788/01608801.pdf?tp=\&isnumber=\&arnumber=1608801}, author = {Montejo-Garai, J R and J A Ruiz-Cruz and Rebollar, J M} }