@article {13_IEEEMWCL_Leal-SevillanoReckJung-KubiakEtAl_SiliconMicromachinedCanonicalTHz,
	title = {Silicon Micromachined Canonical E-Plane and H-Plane Bandpass Filters at the Terahertz Band},
	journal = {IEEE Microwave and Wireless Components Letters},
	volume = {23},
	number = {6},
	year = {2013},
	month = {June},
	pages = {288-290},
	abstract = {In this letter, several bandpass filters operating in the WR-1.5 band (500 to 750 GHz) are presented. The deep reactive ion etching (DRIE) silicon micromachining process is used for the fabrication of the filters. Two canonical filter topologies based on E- and H-plane are implemented. The work presented here has two specific objectives: a) to get important fabrication process parameters, such as tolerances, vertical angles, surface roughness, and repeatability and b) to validate the proper working of the waveguide filters in the terahertz band. These filters do not have any tuning element. Experimental results show better than 10 dB return loss and approximately 1 and 2.5 dB insertion loss (for 6\% fractional bandwidth) for the E- and H-plane topology, respectively. The obtained results are in agreement with fabrication tolerances of 2 micrometers and vertical angles deviations up to 3{\^A}{\textdegree}.},
	keywords = {Deep reactive ion etching (DRIE), filter, micromachining, terahertz, WR-15},
	issn = {1531-1309},
	doi = {10.1109/LMWC.2013.2258097},
	url = {http://ieeexplore.ieee.org/xpls/abs_all.jsp?arnumber=6509458},
	author = {C A Leal-Sevillano and Reck, T J and Jung-Kubiak, C and Chattopadhyay, G. and J A Ruiz-Cruz and Montejo-Garai, J R and Rebollar, J M}
}
@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}
}
@article {12_FED_Montejo-GaraiLeal-SevillanoRuiz-CruzEtAl_SynthesisanddesignPlasma,
	title = {Synthesis and design of waveguide band-stop filters without out-of-band spurious responses for plasma diagnosis},
	journal = {Fusion Engineering and Design},
	volume = {89},
	number = {9},
	year = {2012},
	month = {September},
	pages = {1662-1666},
	issn = {0920-3796},
	doi = {10.1016},
	url = {http://www.sciencedirect.com/science/article/pii/S0920379612003146},
	author = {Montejo-Garai, J R and C A Leal-Sevillano and J A Ruiz-Cruz and Rebollar, J M and Estrada, T}
}
@article {11_MEE_OfliCrespo-ValeroRuiz-CruzEtAl_SEMCADXMicrowaveWg,
	title = {SEMCAD X Microwave: Enhanced Simulation of Waveguide Structures},
	journal = {Microwave Engineering Europe},
	volume = {September},
	year = {2011},
	pages = {12-15},
	abstract = {A general and rigorous formulation is proposed for the analysis of hollow metallic waveguides from the gigahertz to the terahertz band. The analysis is based on a hybrid mode formulation and the Drude model for the dielectric permittivity of metallic conductors. The obtained results for the circular waveguide are compared with the classical microwave approach (surface impedance approximation or Leontovich condition). The validity range of the surface impedance approximation in both the propagation constant and the electromagnetic field pattern is studied. As a consequence, a direct relation between the error in the propagation constant and the electromagnetic field configuration is shown. Moreover, this formulation shows the evolution in the field pattern: from TE=TM modes at microwaves to the so-called Surface Plasmon Polariton at terahertz frequencies},
	issn = {0332-1649},
	url = {http://www.microwave-eetimes.com/en/magazine/mwee-2010.html},
	author = {Ofli, E and Crespo-Valero, P and J A Ruiz-Cruz and C A Leal-Sevillano and Montejo-Garai, J R and Rebollar, J M}
}
@article {11_IJoE_Ruiz-CruzMontejo-GaraiRebollar_Short-slotArbPowerDiv,
	title = {Short-slot E- and H-plane waveguide couplers with an arbitrary power division ratio},
	journal = {International Journal of Electronics},
	volume = {98},
	number = {1},
	year = {2011},
	note = {falta pos en JCR de su a{\~n}o},
	month = {Jan.},
	pages = {11-24},
	abstract = {Short-slot couplers are a particular type of waveguide directional coupler commonly used due to their compact size in comparison with other waveguide configurations. The common short-slot Riblet coupler is used as a 3 dB hybrid (equal power division to the coupled and the through ports) in microwave networks supporting high power and providing good performance over a moderate bandwidth. In this article, the general case of short-slot couplers with arbitrary power division is presented, in E- or H-plane configuration. Moreover, it is shown that the port closer to the input can handle either more or less power than the further port, depending on the design parameters and the length of the main guide of the coupler. Several designs in E- and H-plane are shown to introduce the concept. In addition, two experimental prototypes, with either rectangular waveguide interfaces or coaxial input/output, are manufactured and tested showing good agreement with the expected results.},
	issn = {0020-7217},
	doi = {10.1080/00207217.2010.488913},
	url = {http://www.informaworld.com/smpp/content~db=all~content=a931813059~frm=titlelink},
	author = {J A Ruiz-Cruz and Montejo-Garai, J R and Rebollar, J M}
}
@conference {10_EuCAP_Leal-SevillanoRuiz-CruzMontejo-GaraiEtAl_SimpleModelsTHz,
	title = {Simple Models For The Analysis Of Waveguiding Systems At The Terahertz Band Using Classical Microwave Approaches},
	booktitle = {Proc. 2010 European Conference on Antennas and Propagation (EuCap)},
	year = {2010},
	month = {Apr.},
	pages = {1-5},
	abstract = {Recently the terahertz band has focused so much attention from many research groups with the aim of designing full systems. The first task before designing devices in this band is to characterize waveguide systems. In this contribution the analysis of different waveguides systems in the terahertz band is presented. The analysis is based on a hybrid mode formulation and the Drude model for the dielectric permittivity of the metallic conductor. A comparison between the exact results obtained with this last formulation and those using classical microwave approaches (surface impedance approximation or Leontovich{\^A}{\textasciiacute}s condition) is done in order to determine the validity range of the approximations in both the propagation constant and the electromagnetic field pattern.},
	url = {http://ieeexplore.ieee.org/stamp/stamp.jsp?arnumber=05505379},
	author = {C A Leal-Sevillano and J A Ruiz-Cruz and Montejo-Garai, J R and Rebollar, J M}
}
@article {10_IEEETMTT_Medina-MenaMesa-LedesmaRuiz-CruzEtAl_StudyEOTCircularWg,
	title = {Study of Extraordinary Transmission in a Circular Waveguide System},
	journal = {IEEE Transactions on Microwave Theory and Techniques},
	volume = {58},
	number = {6},
	year = {2010},
	month = {June},
	pages = {1532-1542},
	abstract = {Extraordinary transmission through periodic distributions of sub-wavelength holes made in opaque screens has been demonstrated and exhaustively studied along the last decade. More recently, extraordinary transmission has also been predicted and experimentally observed through electrically small diaphragms located inside hollow pipe waveguides. This last phenomenon cannot be explained in terms of surface waves excited along the periodic system (the so-called surface plasmon polaritons). Transverse resonances can be invoked, however, as a sound explanation for extraordinary transmission in this kind of systems. In this paper, a simple waveguide system, exhibiting exactly the same behavior previously observed in periodic 2-D arrays of holes, is analyzed in depth. Analogies and differences with the periodic case are discussed. The theoretical and experimental results reported in this paper provide strong evidence in favor of the point of view emphasizing the concept of impedance matching versus surface wave excitation. The role of material losses is discussed as an important practical issue limiting the maximum achievable subwavelength transmission level. Most of our conclusions can be applied to both periodic arrays of holes and diaphragms in closed waveguides.},
	issn = {0018-9480},
	doi = {10.1109/TMTT.2010.2048254},
	url = {http://ieeexplore.ieee.org/search/srchabstract.jsp?tp=\&arnumber=5462973\&queryText\%3Dmedina+ruiz-cruz\%26openedRefinements\%3D*\%26searchField\%3DSearch+All},
	author = {Medina-Mena, F and Mesa-Ledesma, F and J A Ruiz-Cruz and Rebollar, J M and Montejo-Garai, J R}
}
@conference {09_URSIESP_Montejo-GaraiRuiz-CruzRebollar_SintElipSinglyMux,
	title = {S{\'\i}ntesis de Filtros El{\'\i}pticos Single-Terminated Sim{\'e}tricos y Asim{\'e}tricos para Multiplexaci{\'o}n},
	booktitle = {Proc. 2009 Simposium Nacional URSI (in Spanish)},
	year = {2009},
	month = {Sept.},
	pages = {1-4},
	abstract = {An extension of the Cauer ladder development for synthesizing singly-terminated filters with symmetric and asymmetric responses is presented. Basically, a driving{\^a}{\texteuro}{\textquotedblleft}point immittance including reactive constant elements is carried out in such a way that provides the transmission zeros. The reactive constant elements are introduced into the synthesis for two reasons. The first is to considerer the possibility of the asymmetric position of transmission zeros in the real frequency axis. The second one is to obtain canonical forms, i.e. networks with the minimum number of elements in the case of symmetrical responses. In order to validate the proposed method, a filter with asymmetrical response has been synthesized, comparing different topologies for its use in multiplexers. This fact is illustrated with a Ku-band elliptic response diplexer designed in H-plane rectangular waveguide.},
	url = {http://w3.iec.csic.es/ursi/articulos_modernos/Cantabria2009/files/Sintesis_URSI_20091240904977.pdf},
	author = {Montejo-Garai, J R and J A Ruiz-Cruz and Rebollar, J M}
}
@conference {09_CNES_Montejo-GaraiRuiz-CruzRebollar_DiplexerAsymmetricSingly,
	title = {Synthesis and Design of a Diplexer with Asymmetric Singly-Terminated Elliptic Ladder Filters},
	booktitle = {Proc. 2009 Int. Workshop on Microwave Filters CNES-ESA},
	year = {2009},
	month = {Nov.},
	pages = {1-6},
	author = {Montejo-Garai, J R and J A Ruiz-Cruz and Rebollar, J M}
}
@article {09_IJRFMiCAE_Montejo-GaraiRuiz-CruzRebollar_SynthesisSinglyEllipticLadderFilters,
	title = {Synthesis of Symmetric and Asymmetric Singly-Terminated Elliptic Ladder Filters for Multiplexing Applications},
	journal = {International Journal of RF and Microwave Computer-Aided Engineering},
	volume = {19},
	number = {4},
	year = {2009},
	month = {July},
	pages = {443-452},
	abstract = {An extension of the Cauer ladder development for synthesizing singly terminated filters with symmetric and asymmetric responses is presented. Basically, a driving-point immittance including reactive constant elements is carried out in such a way that provides the transmission zeros. The reactive constant elements are introduced into the synthesis for two reasons. The first is to consider the possibility of the asymmetric position of transmission zeros in the real frequency axis. The second one is to obtain canonical forms, i.e. networks with the minimum number of elements in the case of symmetrical responses. To validate the proposed method, a filter with asymmetrical response has been synthesized, comparing different topologies for its use in multiplexers. This fact is illustrated with a Ku-band elliptic response diplexer designed in H-plane rectangular waveguide. {\^A}{\textcopyright} 2009 Wiley Periodicals, Inc. Int J RF and Microwave CAE, 2009.},
	keywords = {diplexer, filter synthesis, pole removal, singly terminated, zero-shifting},
	issn = {1096-4290},
	doi = {10.1002/mmce.20366},
	url = {http://www3.interscience.wiley.com/cgi-bin/fulltext/122322557/PDFSTART},
	author = {Montejo-Garai, J R and J A Ruiz-Cruz and Rebollar, J M}
}
@conference {05_URSIUSA_Ruiz-CruzMontejo-GaraiRebollar_Simpleequivalentcircuit,
	title = {Simple equivalent circuit of multi-aperture rectangular iris in rectangular waveguide},
	booktitle = {Proc. 2005 USNC/URSI National Radio Science Meeting},
	year = {2005},
	month = {July},
	pages = {1},
	abstract = {The rejection produced by a multi-apertures iris can be a very useful tool in the design of some kind of filters: a) band pass filters with some improved stop band attenuation as it has been proposed at (A A Kirilenko, MSMW{\textquoteright}2001 Symposium, 690-692), and b) harmonic rejection filters for the dominant and higher waveguide modes (A A Kirilenko,IEEE MTT-S Digest, 373-376). An alternative interpretation of the resonance of this multi-apertures iris in terms of the excitation of a Transverse Electro-Magnetic field (TEM) of the structure has been proposed by the authors of this contribution at (2003 USNC/URSI Symp., 226) and ( 2004 USNC/URSI Symp., 45). Moreover, this interpretation can be useful to control and prevent some spurious resonance that arise at some rectangular waveguide devices, therefore helping the designer to improve their electrical performances. In this paper, with the main aim to implement an efficient computer aided design tool for waveguide filters, a simple equivalent circuit in terms of lumped elements is proposed for multi-apertures iris with the mentioned resonant TEM behaviour. As an example of the proposed equivalent circuit, a classical band pass filter of asymmetrical inductive windows have been modified by introducing slots in the irises to obtain additional stop band attenuation out of band response. This additional attenuation band is achieved without increasing the number of cavities of the filter, therefore with the same dimensions and very similar insertion losses at its band pass. Further information regarding the design process for the Ka-band filter, and results such as fullwave response and the relative convergence problem of the analysis will be commented in the oral presentation.},
	author = {J A Ruiz-Cruz and Montejo-Garai, J R and Rebollar, J M}
}
@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}
}
@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}
}
