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  • A Ku-band RF-MEMS frequency-reconfigurable multimodal bandpass filter

     Contreras Lizarraga, Adrian Arturo; Casals Terre, Jasmina; Pradell Cara, Lluis; Giacomozi, Flavio; Iannacci, Jacopo; Ribó, Miquel
    International journal of microwave and wireless technologies
    Date of publication: 2014
    Journal article

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    In this paper, a uniplanar RF-MEMS second-order bandpass filter with reconfigurable center frequency is presented. It is based on quarter-wavelength slotline resonators and coplanar waveguide (CPW)-to-slotline multimodal immitance inverters (MIIs), which are reconfigured using RF-MEMS switchable CPW air-bridges (SABs). The filter can be adequately explained and designed using multimodal theory and circuit models. A surface micromachining process on high-resistivity silicon substrate was used to fabricate the filter. Experimental results show frequency reconfiguration from 12 to 13 GHz, maintaining the same relative bandwidth, and insertion losses of 4.6 and 4.7 dB, respectively.

  • CPW balun for printed balanced antennas

     Sanchez, Albert Miquel; Ribó, Miquel; Pradell Cara, Lluis; Anguera Pros, Jaume; Andujar, Aurora
    Electronics Letters
    Date of publication: 2014-05-22
    Journal article

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    In coplanar waveguide (CPW) circuits, printed balanced antennas must be excited through baluns. These baluns often feature coplanar-to-slotline transitions that must be tuned and matched by electromagnetic optimisation, and may interfere with the antenna backward radiation. A new CPW balun for printed balanced antennas is presented and modelled. As its multimodal circuit model makes clear, it integrates an impedance-matching network within its structure that can be analytically designed. The balun has been experimentally tested, exhibiting good agreement with its circuit model and a weak electromagnetic interaction with the antenna radiation.

    In coplanar waveguide (CPW) circuits, printed balanced antennas must be excited through baluns. These baluns often feature coplanar-to-slotline transitions that must be tuned and matched by electromagnetic optimisation, and may interfere with the antenna backward radiation. A new CPW balun for printed balanced antennas is presented and modelled. As its multimodal circuit model makes clear, it integrates an impedance-matching network within its structure that can be analytically designed. The balun has been experimentally tested, exhibiting good agreement with its circuit model and a weak electromagnetic interaction with the antenna radiation.

  • Highly efficient class-F RF power amplifiers with very low distortion

     Gilasgar, Mitra; Barlabe Dalmau, Antoni; Pradell Cara, Lluis
    Radio Science Bulletin
    Date of publication: 2013-12
    Journal article

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    This paper presents a novel class-F power amplifiers for mobile applications in which the need for an extra filtering section is eliminated with a proper harmonic tuning structure. Two class-F power amplifiers are presented (900 MHz and 1800MHz bands). The 900 MHz amplifier is able to deliver 38.6 dBm with a PAE of 80.5 % and a total harmonic distortion of 1.2 %. The 1800 MHZ delivers 38.8 dBm and has a PAE of 75%

  • K-band RF-MEMS uniplanar reconfigurable-bandwidth bandpass filter using multimodal immittance inverters

     Contreras Lizarraga, Adrian Arturo; Ribó, Miquel; Pradell Cara, Lluis; Casals Terre, Jasmina; Giacomozzi, Flavio; Iannacci, Jacopo
    Electronics Letters
    Date of publication: 2013-05-23
    Journal article

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  • Uniplanar bandpass filters based on multimodal immitance inverters and end-coupled slotline resonators

     Contreras Lizarraga, Adrian Arturo; Ribó, Miquel; Pradell Cara, Lluis; Blondy, Pierre
    IEEE transactions on microwave theory and techniques
    Date of publication: 2013
    Journal article

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    This paper presents the design and implementation of uniplanar bandpass filters that use end-coupled slotline resonators and a new kind of multimodal immitance inverter. These inverters are based on an asymmetric shunt-short-circuit coplanar waveguide (CPW) transition, and are modeled using a multimodal circuit model, which takes into account both fundamental modes of the CPW (the even and the odd modes). From this model, analytical design expressions for the inverters are obtained. These structures are used as input/output inverters of a new class of compact low-loss arbitrary-order easily reconfigurable uniplanar filters featuring half-wavelength and quarter-wavelength end-coupled resonators. A multimodal model is obtained for these filters, which allows an accurate analysis, design, and prediction of their behavior. By using these multimodal tools, three second- and fourth-order prototypes, and a second-order frequency-tunable prototype, were designed and implemented. The fourth-order filter has an insertion loss of 2.2 dB at 2 GHz with an out-of-band rejection better than 20 dB in an extremelywide frequency band. The frequency-tunable filter features a tuning range from 1 to 1.37 GHz with quasi-constant 3-dB bandwidth from 121 to 135 MHz. The measurements show a good agreement with the proposed multimodal model, thus validating the model and the design methodology.

  • Frequency and bandwidth control of switchable microstrip bandpass filters using RF-MEMS ohmic switches

     Brito, Zabdiel; Llamas, Ignacio; Pradell Cara, Lluis; Giacomozzi, Flavio; Colpo, Sabrina
    International Symposium on RF MEMS and RF Microsystems
    Presentation's date: 2013-07-02
    Presentation of work at congresses

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    In this paper a reconfigurable bandpass filter is designed using ohmic-contact cantilever-type Micro Electro Mechanical Systems (MEMS) switches., Tthe filter can switch between two different states with a center frequency tunable range of 13 % in C band. The topology allows achieving two accurate center frequencies, each associated with a precisely defined bandwidth, using six MEMS ohmic-switches. The design carefully takes into account the external quality factor for both filter states to ensure a good impedance match at each frequency. Coupling coefficients and resonator lengths produce the bandwidths and center frequencies required by design specifications. The filter is designed to have center frequencies of 5.5 and 6.2 GHz, with a fractional bandwidth (FBW) of 5 and 3 %, respectively. Filter specifications were successfully met with the proposed topology. The filter was fabricated on a quartz substrate and measured responses are in good agreement with simulations

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    A very low distortion high efficiency class-F power amplifier at 900 MHz.  Open access

     Gilasgar, Mitra; Barlabe Dalmau, Antoni; Pradell Cara, Lluis
    Simposium Nacional de la Unión Científica Internacional de Radio
    Presentation's date: 2013-09-12
    Presentation of work at congresses

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    This paper presents a novel class-F power amplifier for mobile applications in which with a proper harmonic tuning structure the need for an extra filtering section is eliminated. A class-F power amplifier employing a GaN HEMT device has been designed, fabricated and measured at 900 MHz. The fabricated circuit achieves an excellent harmonic-suppression level and the total harmonic distortion is around 1.2%. It overcomes the narrow band performance of class-F power amplifiers, giving more than 70% efficiency over a 100 MHz bandwidth. Experimental results show that the amplifier is able to deliver 38.5 dBm output power while achieving the state-of-the-art PAE of 80.5% with a peak drain efficiency of 84%, and a power gain of 13.6 dB for an input power of 25 dBm. A good agreement between measurement and simulation results is observed for the proposed structure.

    This paper presents a novel class - F power amplifier for mobile applications in which with a proper harmonic tuning structure the need f or an extra fil tering section is eliminated . A class - F power a mplifier employing a GaN HEMT device has been designed, fabricated and measured at 900 MHz . The fabricated circuit achieves a n excel lent harmonic - suppression level and the t otal h armonic distortion is around 1.2% . It overcomes the narrow band performance of class - F power amplifier s, giving more than 70% efficiency over a 100 MHz bandwidth . Experimental results show that the amplifier is able to deliver 38.5 dBm output power while achieving the state - of - the - art PAE of 8 0.5 % with a peak drain eff iciency of 8 4 % , and a power gain of 13.6 dB for an input power of 25 dBm . A good agreement between measurement and simulation results is observed for the proposed structure.

  • Reconfigurable multimodal bandpass filter based on RF-MEMS switchable CPW air-bridges

     Contreras Bleda, Adrián; Casals Terre, Jasmina; Pradell Cara, Lluis; Giacomozi, Flavio; Iannacci, Jacopo; Ribó i Pal, Miquel
    European Microwave Week
    Presentation's date: 2013-10-08
    Presentation of work at congresses

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    In this paper, a uniplanar RF-MEMS secondorder bandpass filter with reconfigurable centre frequency is presented. It is based on quarter-wavelength slotline resonators and CPW-slotline multimodal immittance inverters (MIIs), which are reconfigured using RF-MEMS switchable CPW airbridges (SABs). The filter can be adequately explained and designed using multimodal theory and circuit models. A surface micromachining process on high-resistivity silicon substrate was used to fabricate the filter. Experimental results show frequency reconfigurability from 12 GHz to 13 GHz, maintaining the same relative bandwidth, and insertion losses of 4.6 dB and 4.7 dB respectively.

  • Reconfigurable uniplanar bandpass filter based on RF-MEMS switched capacitors

     Contreras, Adrián; Pradell Cara, Lluis; Casals Terre, Jasmina; Giacomozzi, Flavio; Iannacci, Jacopo; Ribó, Miquel
    International Symposium on RF MEMS and RF Microsystems
    Presentation's date: 2013-07-02
    Presentation of work at congresses

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    In this paper, an uniplanar RF-MEMS second-order bandpass filter with reconfigurable centre frequency is presented. It is based on half-wavelength slotline resonators, which are loaded using RF-MEMS switches connected to MIM capacitors. Experimental results show frequency reconfigurability from 15 GHz down to 10 GHz

    In this paper a reconfigurable bandpass filter is designed using ohmic-contact cantilever-type Micro Electro Mechanical Systems (MEMS) switches., Tthe filter can switch between two different states with a center frequency tunable range of 13 % in C band. The topology allows achieving two accurate center frequencies, each associated with a precisely defined bandwidth, using six MEMS ohmic-switches. The design carefully takes into account the external quality factor for both filter states to ensure a good impedance match at each frequency. Coupling coefficients and resonator lengths produce the bandwidths and center frequencies required by design specifications. The filter is designed to have center frequencies of 5.5 and 6.2 GHz, with a fractional bandwidth (FBW) of 5 and 3 %, respectively. Filter specifications were successfully met with the proposed topology. The filter was fabricated on a quartz substrate and measured responses are in good agreement with simulations

  • Premio Jóvenes Científicos URSI 2013

     Gilasgar, Mitra; Barlabe Dalmau, Antoni; Pradell Cara, Lluis
    Award or recognition

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  • Multimodal Microwave Filters  Open access

     Contreras Lizarraga, Adrian Arturo
    Defense's date: 2013-11-29
    Department of Signal Theory and Communications, Universitat Politècnica de Catalunya
    Theses

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    En esta tesis se presenta la concepción, diseño e implementación de nuevas topologías de resonadores y filtros de microondas multimodales, utilizando una combinación de tecnologías uniplanares como guía de onda coplanar (CPW), tiras coplanares (CPS) y slotlines. El término "multimodal" se refiere a circuitos uniplanares CPW donde los dos modos fundamentales se propagan (el modo par y el modo impar). Mediante el uso de ambos modos de la CPW, es posible lograr funciones adicionales, tales como generar ceros de transmisión para incrementar el rechazo ó para atenuar frecuencias armónicas, mejorando el rechazo fuera de banda del filtro. Por otra parte, se demostró que mediante el uso de circuitos multimodales es posible reducir la longitud de un filtro convencional hasta 80%. Además de filtros pasobanda se presentan nuevas topologías de filtros de banda eliminada. Los filtros de banda eliminada propuestos hacen uso de resonadores multimodales de onda lenta (slow-wave) para disminuir el área total de los filtros.Este trabajo también abarca el desarrollo de técnicas de síntesis para cada filtro multimodal propuesto. Las ecuaciones de diseño se obtuvieron a partir de circuitos multimodales generalizados disponibles en la literatura. Los circuitos multimodales han sido adaptados para cada caso y modelados como componentes basicos de filtros, tales como inversores de impedancia/admitancia ó elementos concentrados. Mediante el uso de las ecuaciones propuestas, es posible diseñar filtros con una respuesta y ancho de banda predeterminado . El uso de la síntesis propuesta permite un rápido análisis y diseño de filtros multimodales, utilizando simuladores de circuitos de RF comerciales.Adicionalmente, se han demostrado varias topologias de filtros reconfigurables y sintonizables, utilizando dispositivos activos (diodos PIN y varactores) ó MEMS de RF. Estas nuevas topologías demuestran la flexibilidad de los circuitos multimodales. Para poder implemenatar los filtros sintonizables basados en MEMS de RF, se han diseñados , fabricado y medido diferentes conmutadores capacitivos y óhmicos. Como un ejemplo de los grados de libertad adicionales de los circuitos multimodales, se ha diseñado por primera vez un filtro reconfigurable que utiliza puentes de equipotencialidad conmutables, utilizando MEMS de RF.

    This thesis presents the conception, design and implementation of new topologies of multimodal microwave resonators and filters, using a combination of uniplanar technologies such as coplanar waveguide (CPW), coplanar strips (CPS) and slotlines. The term "multimodal" refers to uniplanar circuits in which the two fundamental modes of the CPW propagate (the even and the odd mode). By using both modes of the CPW, it is possible to achieve added functions, such as additional transmission zeros to increase the rejection, or to attenuate harmonic frequencies to improve the out-of-band rejection. Moreover, it is demonstrated that by using multimodal circuits, it is possible to reduce the length of of a conventional filter up to 80%. In addition to bandpass filters, new topologies of compact band-stop filters are developed. The proposed band-stop filters make use of slow-wave resonators to decrease the total area of the filters and achieve compact topologies. This work also addresses the development of synthesis techniques for each multimodal filter. The design equations were obtained from generalized multimodal circuits available in the literature, which have been adapted for each particular case and modeled as basic filter components, such as immitance inverters or lumped elements. By using the proposed synthesis equations, it is possible to design filters with a desired response and relative bandwidth. The use of the proposed synthesis enables a fast analysis and design of multimodal filters using circuit simulators. As an added feature, several reconfigurable and tunable filter topologies were demonstrated, using active devices (PIN diodes and varactors) or RF-MEMS. These new topologies demonstrate the flexibility of multimodal circuits. For the RF-MEMS-based tunable filters, different capacitive and ohmic switches were designed, fabricated and measured. As an example of the additional degrees of freedom using of RF-MEMS and multimodal CPW circuits, a reconfigurable filter using RF-MEMS switchable air-bridges as a reconfiguration device has been demonstrated in this work for the first time.

  • Precise frequency and bandwidth control of switchable microstrip bandpass filters using diode and microelectro-mechanical system technologies

     Brito, Zabdiel; Llamas Garro, Ignacio; Navarro Muñoz, Guillem; Perruisseau Carrier, Julien; Pradell Cara, Lluis; Giacomozzi, Flavio; Colpo, Sabrina
    IET microwaves antennas and propagation
    Date of publication: 2012-04-24
    Journal article

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  • Discretely tuned RF-MEMS bandstop filter with wide tuning range and uniform high rejection

     Llamas-Garro, Ignacio; Brito, Zabdiel; Pradell Cara, Lluis; Giacomozzi, Flavio; Colpo, Sabrina
    Electronics Letters
    Date of publication: 2012-08-16
    Journal article

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    Conmutadores RF-MEMS de baja tensión  Open access

     Contreras Lizarraga, Adrian Arturo; Casals Terre, Jasmina; Pradell Cara, Lluis; Colpo, Sabrina; Iannacci, Jacopo; Ribó, Miquel; Giacomozzi, Flavio
    Simposium Nacional de la Unión Científica Internacional de Radio
    Presentation's date: 2012
    Presentation of work at congresses

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    This work shows experimental results of capacitive and ohmic RF-MEMS switches with low actuation voltage. The isolation of capacitive switches is better than 20 dB from 15 GHz and up to 80 GHz according to simulations. The ohmic-contact switch can be used in coplanar waveguide (CPW) reconfigurable multimodal circuits, for a selective use of the CPW odd-mode. The CPW odd-mode isolation in the down state is better than 20 dB up to 8 GHz and better than 10 dB up to 30 GHz.

  • Low voltage capacitive and Ohmic RF-MEMS Switches

     Contreras Lizarraga, Adrian Arturo; Casals Terre, Jasmina; Pradell Cara, Lluis; Giacomozzi, Flavio; Colpo, Sabrina; Iannacci, Jacopo; Ribó, Miquel
    International Symposium on RF MEMS and RF Microsystems
    Presentation's date: 2012
    Presentation of work at congresses

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    This work presents experimental results of capacitive and ohmic-contact RF-MEMS switches. The suspension has been designed to compensate stress-gradient effects, and to obtain low pull-in voltages. The measured actuation voltage is 12 V for devices with an air gap of 1.3 µm. The measured isolation of the capacitive switches is better than 20 dB for frequencies above 15 GHz, and better than 30 dB from 31 GHz up to 80 GHz according to simulations. The ohmic-contact switch can be used to control the odd mode in coplanar waveguide (CPW) reconfigurable multimodal circuits. The CPW odd-mode isolation of the ohmic-contact switch in its down state is better than 20 dB up to 8 GHz and better than 10 dB up to 30 GHz.

  • Filtro paso-banda con control preciso de frecuencia central y ancho de banda usando interruptores RF MEMS

     Brito, Zabdiel; Llamas, Ignacio; Perruisseau Carrier, Julien; Pradell Cara, Lluis; Giacomozzi, Flavio; Colpo, Sabrina
    Simposium Nacional de la Unión Científica Internacional de Radio
    Presentation's date: 2012-09-12
    Presentation of work at congresses

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    In this paper a reconfigurable bandpass filter is presented. The filter is able to switch between two different states with a center frequency tunable range of 24 % in C band. Center frequency and bandwidth are precisely met by a switchable filter topology that includes two folded resonator extensions switched by four ohmic-contact cantilever-type Micro Electro Mechanical Systems (MEMS) switches. The filter was designed to have center frequencies of 5 and 6.2 GHz, with a fractional bandwidth of 7 and 3 %, respectively. The filter was fabricated on a quartz substrate and measured responses are in good agreement with simulations. Filter specifications were successfully met with the proposed topology.

    Postprint (author’s final draft)

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    A RF-MEMS switchable CPW air-bridge  Open access

     Contreras, Adrián; Casals Terre, Jasmina; Pradell Cara, Lluis; Giacomozzi, Flavio; Colpo, Sabrina; Iannacci, Jacopo; Ribó, Miquel
    European Microwave Conference
    Presentation's date: 2012-10-30
    Presentation of work at congresses

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    This work presents a new shunt-Type ohmic contact RF-MEMS switch specifically designed as a switchable CPW air bridge. The switch can be used in coplanar waveguide (CPW) reconfigurable multimodal circuits, for a selective use of the CPW odd-mode. The bridge is anchored using folded-beam suspensions, in such a way that two points at each end of the bridge remain free to contact the ground planes of the CPW. The suspension has been designed to compensate stress gradients effects and to lower actuation voltage. In the actuated (ON) state, the switch isolation to the odd mode is better than 20dB up to 8GHz and 10dB up to 30GHz. 2012 European Microwave Assoc.

    This work presents a new shunt-type ohmic contact RF-MEMS switch specifically designed as a switchable CPW air bridge. The switch can be used in coplanar waveguide (CPW) reconfigurable multimodal circuits, for a selective use of the CPW odd-mode. The bridge is anchored using folded-beam suspensions, in such a way that two points at each end of the bridge remain free to contact the ground planes of the CPW. The suspension has been designed to compensate stress gradients effects and to lower actuation voltage. In the actuated (ON) state, the switch isolation to the odd mode is better than 20dB up to 8GHz and 10dB up to 30GHz.

    Postprint (author’s final draft)

  • RF-MEMS uniplanar 180° phase switch based on a multimodal air-bridged CPW cross

     Llamas, Marco Antonio; Girbau, David; Ribó, Miquel; Pradell Cara, Lluis; Giacomozzi, Flavio; Colpo, Sabrina
    IEEE transactions on microwave theory and techniques
    Date of publication: 2011-07
    Journal article

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    In this paper, a new compact broadband uniplanar 180 phase switch, based on an air-bridged coplanar-waveguide (CPW) cross loaded with two capacitive-contact microelectromechancial systems (MEMS) switches in opposed (ON/OFF) states, is presented. The two phase-switch states 0 180 are defined by actuating the MEMS switches from ON/OFF to OFF/ON. The asymmetry in the states of the MEMS switches results in a complex multimodal interaction between the two fundamental even and odd CPW modes at the air-bridged cross. Using the multimodal theory, the phase switch is analyzed, its frequency-independent 180 -phase-shift properties are proven, and a set of design equations for perfect port matching are derived. A multimodal circuit model for the phase switch is then presented, and design equations and conditions for compact phase switches are derived. Finally, a very compact phase switch is designed and fabricated using an eight-mask surface micromachining process, featuring a measured phase shift of 180 1.8 in a very wide frequency range (1–30 GHz) and an insertion loss better than 2.1 dB in the design band (10–20 GHz). Experimental results are in very good agreement with electromagnetic and multimodal circuit simulations, thus alidating the proposed approach and design procedure.

  • Polymer-based micromachined rectangular coaxial filters for millimeter-wave applications

     Jaimes-Vera, Aline; Llamas-Garro, Ignacio; Ke, Maolong; Wang, Y.; Lancaster, Michael J.; Pradell Cara, Lluis
    International journal of microwave and wireless technologies
    Date of publication: 2011-04
    Journal article

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    In this paper, micromachined devices for millimeter-wave applications at U- and V-bands are presented. These structures are designed using a rectangular coaxial line built of gold-coated SU-8 photoresist layers, where the coaxial center conductor is suspended in air by stubs. The designs include a stepped coplanar waveguide (CPW)-to-coaxial transition at 63 GHz, with an insertion loss of 0.39 dB at 67.75 GHz and a return loss better than 210 dB across the band of operation between 54.7 and 70.3 GHz. Two filters have been designed; one centered at 42 GHz with a 10% bandwidth, and another at 63 GHz with a 5% bandwidth. Measured insertion losses of 0.77 and 2.59 dB were obtained for these filters, respectively. Measured return loss lower than 13.8 dB over the passband was achieved for both designs. The structures presented in this paper involve a low-cost manufacturing process suitable to produce integrated subsystems at millimeter waves.

  • A highly-repeatable, broadband 180º phase switch for integrated MEMS processes

     Llamas, Marco Antonio; Girbau, David; Ribó, Miquel; Pradell Cara, Lluis; Giacomozzi, Flavio; Colpo, Sabrina; Coccetti, Favio; Aouba, StephaneaOUBA
    International Symposium on RF MEMS and RF Microsystems
    Presentation's date: 2011-06-28
    Presentation of work at congresses

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    A broadband 0º/180º phase switch based on a slotline-coplanar-waveguide cross loaded with two MEMS switches in opposed (ON/OFF or OFF/ON) states, is reported. The fabrication was made on high-resistivity silicon substrates using the FBK-irst and LAAS-CNRS surface micromachining processes, showing a high repeatability. The measured phase shift is 180º +0º/-7º in the extremely wide frequency range 1–30 GHz.

  • U-Band micromachined coaxial filter

     Jaimes Vera, Edith Aline; Llamas Garro, Ignacio; Ke, Maolong; Wang, Yi; Lancaster, Michael J.; Pradell Cara, Lluis
    IEEE International Microwave Workshop Series on Millimeter Wave Integration Technologies
    Presentation's date: 2011-09-16
    Presentation of work at congresses

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    This paper presents a micromachined filter for millimeter-wave applications operating at U-band. The structure was designed using a rectangular coaxial line with the center conductor suspended in air. The rectangular coaxial cables have been optimized to provide a low attenuation constant. The design includes a coplanar waveguide (CPW)-to-coaxial transition to interface the device with other components, or coplanar probes for measurements. The filter has been designed with a center frequency of 42 GHz and a 10% fractional bandwidth. A measured insertion loss of 0.77 dB has been obtained. This structure involves a low-cost micromachining manufacturing process using SU-8 photo resist which is very attractive for the implementation of integrated millimeter wave subsystems.

  • A novel tunable multimodal bandpass filter

     Contreras Lizarraga, Adrian Arturo; Pradell Cara, Lluis; Ribó, Miquel
    European Microwave Week
    Presentation's date: 2011-10-11
    Presentation of work at congresses

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    This paper presents a novel uniplanar tunable bandpass filter. In this filter, each resonator can be reconfigured easily using PIN diodes or MEMS switches. Design equations are derived from a simple circuit model which takes into account the multimodal behavior of the coplanar waveguide. Experimental measurements of a 2-GHz prototype, featuring reconfigurable bandwidth and low losses, validate the filter topology and the proposed multimodal model.

  • Filtro uniplanar multimodal reconfigurable

     Contreras Lizarraga, Adrian Arturo; Ribó, Miquel; Pradell Cara, Lluis
    Simposium Nacional de la Unión Científica Internacional de Radio
    Presentation's date: 2011-09-08
    Presentation of work at congresses

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    A uniplanar filter based on two coplanar-waveguide odd-mode resonators is presented. The resonator feeding point is easily reconfigured using PIN diodes. As a result, the filter features reconfigurable bandwidth. A multimodal circuit model which takes into account the interaction between the two coplanar waveguide fundamental modes (even and odd) is derived and used to design a 2-GHz prototype. The experimental results show two relative-bandwidth states (14% and 21%) and low loss (1.1 dB), thus validating the filter concept and multimodal analysis.

  • Diseño de tecnologias integradas reconfigurables en banda milimétrica

     Casals Terre, Jasmina; Barlabe Dalmau, Antoni; Contreras Lizarraga, Adrian Arturo; Pradell Cara, Lluis
    Participation in a competitive project

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  • Yago Subsistemas reconfigurables

     Pradell Cara, Lluis
    Participation in a competitive project

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  • Planck pre-launch status: the planck mission

     Tauber, Jan A.; Mandolesi, Nazzareno; Pujet, J.L.; Banos, T.; Bersanelli, Marco; Bouchet, R.C.; Butler, Chris; Charra, J.; Crone, Gerald; Dodsworth, John; Efstathiou, George; Gispert, Richard; Guyot, Guy; Gregorio, A.; Juillet, J. J.; Lamarre, J. M.; Laureijs, R. J.; Lawrence, C. R.; Nørgaard-Nielsen, H. U.; Passvogel, T.; Reix, J. M.; Texier, D.; Pradell Cara, Lluis; Vibert, L.; Zacchei, A.; Ade, P.A.R; Aghanim, N.; Aja, B.; Alippi, E.; Aloy, L.; Armand, P.; Arnaud, M.; Arondel, A.; Arreola-Villanueva, A.; Artal, E.; Artina, E.; Arts, A.; Ashdown, M.; Ashdown, M.; Aumont, J.; Azzaro, M.; Bacchetta, A.; Baccigalupi, C.; Baker, M.; Balasini, M.; Balbi, A.; Banday, A.J.; Barbier, G.; Barreiro, R.B.; Bartelmann, M.; Battaglia, P.; Battaner, E.; Benabed, K.; Beney, J. L.; Beneyton, R.; Bennett, K.; Benoit, A.; Bernard, J. P.; Bhandari, P.; Bhatia, R.; Biggi, M.; Biggins, R.; Billig, G.; Blanc, Y.; Blavot, H.; Bock, J. J.; Bonaldi, A.; Bond, R.; Bonis, J.; Borders, J.; Borrill, J.; Boschini, L.; Boulanger, F.; Bouvier, J.; Bouzit, M.; Bowman, R.; Bréelle, E.; Bradshaw, T.; Braghin, M.; Bremer, M.; Brienza, D.; Broszkiewicz, D.; Burigana, C.; Burkhalter, M.; Cabella, P.; Cafferty, T.; Cairola, M.; Cairola, M.; Caminade, S.; Camus, P.; Cantalupo, C. M.; Cappellini, B.; Cardoso, J. F.; Carr, R.; Catalano, A.; Cayón, L.; Cesa, M.; Chaigneau, M.; Challinor, A.
    Astronomy and astrophysics
    Date of publication: 2010-09-15
    Journal article

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  • A new compact band-pass filter based on an asymmetric short-circuited spurline resonator

     Rodríguez Cepeda, P.; Ribó, Miquel; Pajares, F.J.; Sánchez, A.M.; Regué, J.R.; Pérez, A.; Pradell Cara, Lluis
    Microwave and optical technology letters
    Date of publication: 2010-03-19
    Journal article

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  • FULLY ADAPTABLE BAND-STOP FILTER USING VARACTOR DIODES

     Musoll Anguiano, Carles; Llamas Garro, Ignacio; Brito Brito, Zabdiel; Pradell Cara, Lluis; Corona Chávez, Alonso
    Microwave and optical technology letters
    Date of publication: 2010-03
    Journal article

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  • MEMS-Based 180 degrees Phase Switch for Differential Radiometers

     Llamas, Marco Antonio; Girbau, David; Ribó, Miquel; Pradell Cara, Lluis; Lázaro Guillén, Antonio; Giacomozzi, Flavio; Margesin, Benno
    IEEE transactions on microwave theory and techniques
    Date of publication: 2010-05
    Journal article

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  • Tunable dual-band filters based on capacitive-loaded stepped-impedance resonators

     Pradell Cara, Lluis; Girbau Sala, David; Pérez, Albert; Lázaro Guillén, Antonio; Martínez, Esther; Villarino, Ramon
    International journal of microwave and wireless technologies
    Date of publication: 2010
    Journal article

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  • Tunable dual-band resonators for communication systems

     Girbau, David; Lazaro, Antonio; Pérez, Albert; Martínez, Ester; Pradell Cara, Lluis; Villarino, Ramon
    International journal of microwave and wireless technologies
    Date of publication: 2010-06-01
    Journal article

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    This paper proposes the design of tunable dual-band resonators for multi-band multi-standard systems. The main objective is to provide frequency tunability in the second resonance while maintaining the first resonance fixed. To this end, two tunable resonators are proposed: the capacitive-loaded stepped-impedance resonator and the capacitive-loaded hole resonator. The work is divided into two main parts. In the first part, an in-depth analysis of the capacitive-loaded stepped-impedance resonator (SIR) structure is done; it provides analytical closed-form design equations that ease the resonator design in contrast to the several approaches available in the literature to date. The analysis is also particularized to the case of the capacitive-loaded constant-section resonator and extended to the capacitive-loaded hole resonator. In addition, a study of the quality factor in capacitively tuned SIRs is also provided. In the second part, resonators are integrated in three dual-band tunable filters, one based on the capacitive-loaded constant-section resonator, another one on the capacitive-loaded SIR, and finally on the capacitive-loaded hole resonator. Two of these filters demonstrate operation in wireless local-area network frequency bands, with a fixed first band at 2.45 GHz and a second band which can be tuned between 5.75 and 5.25 GHz.

  • Switchable bandpass filter for WiFi-UMTS reception standards

     Brito Brito, Zabdiel; Llamas Garro, Ignacio; Navarro Muñoz, Guillem; Perruisseau Carrier, Julien; Pradell Cara, Lluis
    Electronics Letters
    Date of publication: 2010-06-24
    Journal article

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    Modelado circuital multimodal de un resonador pasobanda reconfigurable  Open access

     Contreras Lizarraga, Adrian Arturo; Ribó, Miquel; Pradell Cara, Lluis
    Simposium Nacional de la Unión Científica Internacional de Radio
    Presentation's date: 2010-09-15
    Presentation of work at congresses

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    In this work, we present a simple uniplanar bandpass resonator that can be used for the development of reconfigurable uniplanar filters. The multimodal behaviour of the coplanar waveguide is taken into account for the design of the resonator. We show that a simple multimodal model can be used to represent the proposed structure. Experimental measurements validate the accuracy of the proposed model.

  • Dispositivos coaxiales micromecanizados para banda milimétrica

     Jaimes Vera, Edith Aline; Pradell Cara, Lluis; Llamas-Garro, Ignacio; Maolong, Ke; Wang, Yi; Lancaster, Michael J.
    Simposium Nacional de la Unión Científica Internacional de Radio
    Presentation's date: 2010-09-15
    Presentation of work at congresses

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  • Diplexor reconfigurable para estándares de transmisión y recepción WiFi-UMTS

     Brito, Zabdiel; Llamas Garro, Ignacio; Navarro Muñoz, Guillem; Perruisseau Carrier, Julien; Pradell Cara, Lluis
    Simposium Nacional de la Unión Científica Internacional de Radio
    Presentation's date: 2010
    Presentation of work at congresses

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    In this paper a reconfigurable diplexer for WiFi and UMTS transmit and receive bands is presented. The diplexer has four possible frequency and bandwidth states, and consists of two reconfigurable filters connected by an SPDT switch. Simulated and measured results show a very good agreement. The diplexer specifications were successfully matched with the proposed topology.

  • RF-MEMS uniplanar 180º Phase Switch based on switching between two out-of-phase paths

     Llamas Morote, Marco Antonio; Ribó, Miquel; Girbau Sala, David; Pradell Cara, Lluis; Lázaro Guillén, Antonio; Giacomozzi, Flavio; Margesin, Benno
    International Conference on RF MEMS and RF Microsystems
    Presentation's date: 2010-06-28
    Presentation of work at congresses

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    A phase switch based on switching between two twoport passive networks with a phase difference of 180º is reported. Two RF MEMS single-pole-double-throw structures are used to select the phase path. The fabrication is made on both highresistivity silicon and quartz substrates using the eight-mask FBK-irst surface micromachining process. The measured phase shift is 180º±5º in the frequency range 14−20 GHz on quartz wafers and in the range 8−20 Ghz on silicon wafers.

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    DARFM - Introduction to narrow-band matching networks  Open access

     Torres Torres, Francisco; Pradell Cara, Lluis; Miranda, Jorge
    Date: 2010-03-01
    Report

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  • DARFM - Impedance, transformers and tapers  Open access

     Torres Torres, Francisco; Pradell Cara, Lluis
    Date: 2010-03-01
    Report

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  • Precise frequency and bandwidth control of microstrip switchable bandstop filters

     Brito Brito, Zabdiel; Llamas Garro, Ignacio; Pradell Cara, Lluis
    Microwave and optical technology letters
    Date of publication: 2009-08
    Journal article

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  • Selectivity-tuned bandpass filter

     Brito Brito, Zabdiel; Llamas Garro, Ignacio; Pradell Cara, Lluis
    Electronics Letters
    Date of publication: 2009-09
    Journal article

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  • LFI 30 and 44 GHz receivers Back-End Modules

     ARTAL LATORRE, EDUARDO; Aja, B; De la Fuente, M. L.; Pascual, J P; Mediavilla, A; Martinez Gonzalez, Enrique; Pradell Cara, Lluis; de Paco Sánchez, Pedro Antonio; Bara, Marc; Blanco, E; Garcia, E; Davis, R.; Kettle, D; Roddis, N; Wilkinson, A.; Bersanelli, M; Mennella, A; Tomasi, M.; Butler, R C; Cuttaia, F.; Mandolesi, N; Stringhetti, L
    Journal of instrumentation
    Date of publication: 2009-12
    Journal article

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  • A method for characterization of intermodulation distortion produced in mems switches

     Girbau Sala, David; Pradell Cara, Lluis; Lazaro, A; Peyrou, D; Pons, P; Calmon, P
    Microwave and optical technology letters
    Date of publication: 2009-02
    Journal article

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  • Dual-band bandpass filter based on a hole resonator

     Girbau, D; Lazaro, A; Perez, A; Pradell Cara, Lluis
    Microwave and optical technology letters
    Date of publication: 2009-07
    Journal article

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  • A Rigorous Multimodal Analysis and Design Procedure of a Uniplanar 180 degrees Hybrid

     Llamas, MA; Girbau, D; Pradell Cara, Lluis; Ribó, Miquel
    IEEE transactions on microwave theory and techniques
    Date of publication: 2009-07
    Journal article

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  • Tunable dual-band bandpass filter for WLAN applications

     Girbau, D; Lazaro, A; Martínez, Esther; Masone, D; Pradell Cara, Lluis
    Microwave and optical technology letters
    Date of publication: 2009-06
    Journal article

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    Characterization of dynamics in RF-MEMS switches  Open access

     Llamas, Marc; Girbau, David; Pradell Cara, Lluis; Lázaro, Antoni; Giacomozzi, Flavio; Colpo, Sabrina
    International Conference on RF MEMS and RF Microsystems
    Presentation's date: 2009-07-06
    Presentation of work at congresses

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    This paper proposes a new method to measure dynamics and power handling of RF microelectromechanical systems (MEMS) devices based on a mobile membrane. The method uses in-phase/quadrature demodulation of an RF signal proportional to the reflection coefficient of the measured device, which contains information of its mechanical properties, such as actuation and release times and instantaneous position of the mobile membrane. Both one-port (capacitors) and two-port devices (switches and extended tuning-range capacitors) can be measured. Its main advantage is the capability of obtaining information from both magnitude and phase variations of the device reflection coefficient to characterize its dynamics and power handling. It is shown that detecting phase is advantageous in high quality factor capacitors, where the magnitude of the reflection coefficient is nearly constant for any position of the mobile membrane. Open-short-load calibration of the system is provided in order to obtain absolute measurements, which are necessary for power-handling characterization. The performances of the proposed method are demonstrated by comparison to systems based on detection of the magnitude of the reflection coefficient. A MEMS capacitor is characterized in terms of dynamics—actuation and release times, and mechanical resonance frequency—and in terms of power handling—membrane instantaneous position and phase and tuning range variation.

  • Filtros para un cabezal de comunicaciones entre vehículos

     Brito Brito, Zabdiel; Llamas Garro, Ignacio; Navarro Muñoz, Guillem; Perruisseau Carrier, Julien; Pradell Cara, Lluis
    Simposium Nacional de la Unión Científica Internacional de Radio
    Presentation's date: 2009-09-16
    Presentation of work at congresses

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    Characterizing a Tune-all bandstop filter  Open access

     Musoll, Carles; Llamas, Ignacio; Brito, Zabdiel; Pradell Cara, Lluis; Corona, Alfonso
    IEEE MTT-S Int. Microwave Workshop Series on Signal Integrity and High-Speed Interconnects
    Presentation's date: 2009-02-19
    Presentation of work at congresses

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    In this paper a reconfigurable bandstop filter able to reconfigure central frequency, bandwidth and selectivity for fine tuning applications is presented. The reconfigurable filter topology has four poles and a quasielliptic bandstop filter response. The filter is tuned by varactor diodes placed at different locations on the filter topology. The varactors are voltage controlled in pairs due to filter symmetry for central frequency and bandwidth control. An additional varactor is placed on a crossing line to move a pair of transmission zeros, closer or farther to the filter central frequency, which tunes filter selectivity. The filter has a tuneable fractional bandwidth range from 11.51 to 15.46%, a tuneable central frequency range from 1.346 to 1.420 GHz and a selectivity tuning range from 0.37 to 0.40 dB/MHz.

  • Filtros sintonizables de banda dual basados en resonadores de salto de impedancia cargados capacitivamente

     Girbau, David; Lázaro, Antoni; Pérez, Albert; Martínez, Ester; Pradell Cara, Lluis; Villarino Villarino, Ramon
    Simposium Nacional de la Unión Científica Internacional de Radio
    Presentation's date: 2009-09-17
    Presentation of work at congresses

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    Capacitive and resistive RF-MEMS switches 2.5D & 3D electromagnetic and circuit modelling  Open access

     Llamas, Marc; Girbau, David; Pausas, Esther; Pradell Cara, Lluis; Aouba, StephaneaOUBA; Villneuve, C; Puyal, Vincent; Pons, Patrick; Plana, Robert; Giacomozzi, Flavio; Colpo, Sabrina
    Spanish Conference on Electron Devices
    Presentation's date: 2009-02-11
    Presentation of work at congresses

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    this paper proposes different strategies for the electrical modelling of capacitive and resistive RF-MEMS switches which take into account the dependence of the electrical performance on the mechanical properties and technological processes. The EM modelling of MEMS switches is addressed with 2.5D and 3D full wave EM softwares. More specifically, ADS-MomentumTM (2.5D) and EMDSTM (3D) from Agilent Technologies are used. Capacitive RF-MEMS switches were fabricated with the LAAS-CNRS 6-mask RF-MEMS process in Toulouse, France, and resistive RF-MEMS switches were fabricated with the FBK-irst 8-mask RF-MEMS process in Trento, Italy. It is shown that, by applying the proposed strategies, 2.5D and 3D simulations are in good agreement with characterization results.