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

     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.

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

     Contreras, Adrián; Casals Terre, Jasmina; Pradell Cara, Lluis; Giacomozi, Flavio; Iannacci, Jacopo; Ribó, 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.

  • 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%

  • 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.

  • Multimodal Microwave Filters

     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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  • RFID Multiantenna Systems for Wireless Communications and Sensing  Open access

     Capdevila Cascante, Santiago
    Defense's date: 2013-02-15
    Department of Signal Theory and Communications, Universitat Politècnica de Catalunya
    Theses

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    Many scientific, industrial and medical applications require the measurement of different physical parameters in order to collect information about the spatially distributed status of some process. Very often this information needs to be collected remotely, either due to the spatial dispersion of the measurement points or due to their inaccessibility. A wireless embedded self-powered sensor may be a convenient solution to be placed at these inaccessible locations. This thesis is devoted to study the analytical relation governing the electromagnetic coupling between a reader and a embeddable self-powered sensor, based on radio frequency identification (RFID) technology, which is capable of wirelessly retrieving the status of physical parameters at a remote and inaccessible location. The physical parameter to be sensed may be the electromagnetic (EM) field existing at that location (primary measurement) or the indirect measurement of other parameters such as the temperature, humidity, etc. (secondary measurement). Given the simplicity of the RFID solution (highly embeddable properties, scavenging capabilities, penetration and radio coverage characteristics, etc.) the measurement can be done at a single location, or it can be extended to a set of measuring locations (an array or grid of sensors). The analytical relation is based on a reciprocity formulation studying the modulation of the scattered field by the embedded sensor in relation with the incident field, and allows to define a set of quality parameters of interest for the optimum design of the sensors. Particular attention is given to the scavenging circuitry as well as to the antenna design relevant to the sensing objective. In RFID tags, the existence of an RF harvesting section is an improvement with respect to conventional scattering field probes since it removes the need of DC biasing lines or optical fibers to modulate the sensor. However, this harvesting section introduces non-linearities in the response of the sensor, which requires a proper correction to use them as EM-field probes, although the characterization of the non-linearities of the RFID tag cannot be directly done using a conventional vector network analyzer (VNA), due to the requirements of an RFID protocol excitation. Due to this, this thesis proposes an alternative measurement approach that allows to characterize the different scattering states used for the modulation, in particular its non-linear behavior. In addittion, and taking this characterization as the starting point, this thesis proposes a new measurement setup for EM-field measurements based on the use of multiple tones to enlarge the available dynamic range, which is experimentally demonstrated in the measurement of a radiation pattern, as well as in imaging applications. The RFID-based sensor response is electromagnetically sensitive to the dielectric properties of its close environment. However, the governing formulation for the response of the probe mixes together a set of different contributions, the path-loss, the antenna impedance, the loads impedance, etc. As a consequence, it is not possible to isolate each contribution from the others using the information available with a conventional RFID sensor. This thesis mathematically proposes and experimentally develops a modification of the modulation scheme to introduce a new set of multi-load scattering states that increases the information available in the response and properly isolate each term. Moreover, this thesis goes a step forward and introduces a new scattering state of the probe sensitive to temperature variations that do not depend on the environment characteristics. This new configuration enables robust environmental sensing in addition to EM-field measurements, and sensing variations of the dielectric properties of the environment.

  • 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.

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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.

  • 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)

  • 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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  • MICROMACHINED POLYMER BASED COMPONENTS FOR HIGHLY INTEGRATED MILLIMETERWAVE SUBSYSTEMS  Open access

     Jaimes Vera, Edith Aline
    Defense's date: 2012-03-16
    Department of Signal Theory and Communications, Universitat Politècnica de Catalunya
    Theses

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    La región de microondas en el espectro electromagnético tiene propiedades únicas que le permiten a las señales propagarse a través de la atmósfera bajo casi cualquier condición climática, ésta es la razón por la cual los sistemas de microondas han tenido un enorme impacto sobre la sociedad. En los últimos años se ha presentado una importante expansión en las comunicaciones móviles y en las redes de área local, emergiendo nuevas aplicaciones a frecuencias micro/milimétricas, tales como: la transmisión satelital a 35 GHz, las redes de área local de banda ancha a 60 GHz, comunicación entre vehículos a 63 GHz o en radares para evitar colisiones entre vehículos a 77 GHz. A medida que estas aplicaciones han emigrado a frecuencias más elevadas, las limitaciones de las tecnologías convencionales han sido visibles. Por lo cual en los últimos años se ha presentado un creciente interés en el desarrollo de nuevas técnicas de fabricación para la implementación de dispositivos de microondas; las cuales ofrezcan un mejor rendimiento del dispositivo a la vez que una reducción en sus dimensiones y en los costos de fabricación. El principal objetivo de este trabajo ha sido la implementación de dispositivos de filtrado en un amplio rango de frecuencias (banda X, U y V). Las topologías aquí presentadas son novedosas al introducir resonadores y líneas de alimentación suspendidas en aire, donde el uso de aire como dieléctrico permite obtener un factor de calidad mayor. Además el proceso de fabricación es relativamente simple y de bajo costo, ofreciendo estructuras compactas las cuales pueden ser altamente integradas. En la implementación de los dispositivos se utilizaron técnicas de maquinado convencional para los diseños en la banda X y técnicas de micromaquinado en SU-8 en los dispositivos de las bandas U y V. Las estructuras para la banda X fabricadas mediante maquinado convencional sirvieron como validación de las topologías a frecuencias más elevadas. Las estructuras diseñadas han demostrado la viabilidad de las topologías para un amplio rango de frecuencias, obteniendo resultados satisfactorios en cuanto a las prestaciones del dispositivo.

    The microwave region in the electromagnetic spectrum has properties that allow signals to propagate through the atmosphere under almost any weather condition, this is the reason why microwave systems have had an enormous impact on society. In recent years there has been a major expansion in mobile communications and local area networks, emerging new applications at micro/millimeterwave frequencies, such as: satellite transmission at 35 GHz, wideband local area networks at 60 GHz, communication among vehicles at 63 GHz or vehicular collision avoidance radar at 77 GHz. As these applications have migrated to higher frequencies, the limitations of conventional technologies have been visible. Therefore in recent years there has been a growing interest in the development of new manufacturing techniques for the implementation of microwave devices; which offer better device performance as well as a reduction in the size and manufacturing costs. The main objective of this work has been the implementation of filtering devices in a wide range of frequencies (X, U and V-band). The topologies presented are novel introducing resonators and air suspended feed lines, where the use of air as dielectric allows a higher quality factor. Besides manufacturing process is relatively simple and inexpensive, providing compact structures which can be highly integrated. In the implementation of the devices were used conventional machining techniques for X-band designs and micromachining techniques in SU-8 for U and V-band desings. The X-band structures manufactured by conventional machining served as validation of the topologies at higher frequencies. The designed structures have shown the feasibility of the topologies for a wide range of frequencies, with satisfactory results regarding the performance of the device.

  • 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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  • 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.

  • 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 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.

  • 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.

  • 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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    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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  • 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.

  • 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.

  • 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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  • Microwave integrated tunable filters

     Brito Brito, Zabdiel
    Defense's date: 2010-06-21
    Department of Signal Theory and Communications, Universitat Politècnica de Catalunya
    Theses

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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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    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.

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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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  • 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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    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.

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

     Girbau, David; Lázaro, Antoni; Pérez, A.; Martínez, Ester; Pradell Cara, Lluis; Villarino, Ramon
    European Microwave Week
    Presentation's date: 2009-10-01
    Presentation of work at congresses

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    This paper proposes the design of tunable dual-band filters for multi-band multi-standard systems. The main objective is to provide frequency tunability in the second band while maintaining the first band fixed. To this end, the capacitive-loaded stepped-impedance resonator is used. The work is divided into two main parts. In the first part, a deep analysis of the capacitive-loaded stepped-impedance resonator structure is done, which provides analytical closed-form design equations which eases their design in front of the several approaches available in the literature up to now. The analysis is also particularized for the case of the capacitive-loaded uniform resonator. In the second part, resonators are integrated in two dual-band tunable filters.

  • Circuitos de microondas uniplanares multimodales, reconfigurables

     Llamas Morote, Marco Antonio
    Defense's date: 2009-09-14
    Department of Signal Theory and Communications, Universitat Politècnica de Catalunya
    Theses

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  • UMTS-WiFi switchable bandpass filter

     Brito Brito, Zabdiel; Llamas Garro, Ignacio; Navarro Muñoz, Guillem; Perruisseau Carrier, Julien; Pradell Cara, Lluis
    European Microwave Week
    Presentation's date: 2009
    Presentation of work at congresses

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    In this paper a reconfigurable bandpass filter able to switch between WiFi and UMTS transmit band standards is presented. The filter is designed in such a way that center frequency and bandwidth specifications are precisely met by defining a switchable filter topology that includes two folded resonator extensions switched by two PIN diodes. Design specifications require two center frequency states, one at 2.440 GHz with an 80 MHz bandwidth and a second center frequency state at 1.955 GHz with a 140 MHz bandwidth for the WiFi and UMTS transmit bands, respectively. Filter simulations were performed to match the required filter specifications. Measured results on the filter show a very good agreement with the simulations where a 2.428 GHz center frequency with a 71 MHz bandwidth was obtained for the WiFi state, and a 1.939 GHz center frequency with a 144 MHz bandwidth was obtained for the UMTS filter state. The simulated filter insertion losses were -3.339 and -3.796 dB for the WiFi and UMTS states, respectively. Measured insertion losses were -3.345 and -3.837 dB for the WiFi and UMTS states, respectively. The filter specifications were successfully matched with the proposed filter topology, where simulated and measured responses are in good agreement.

  • 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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  • 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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  • 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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  • Design and Optimization of RF Power LDMOS Transistors for Base Station Applications

     CORTES MAYOL, IGNACIO
    Defense's date: 2008-02-08
    Department of Electronic Engineering, Universitat Politècnica de Catalunya
    Theses

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  • Microstrip Switchable Bandstop Filter using PIN Diodes with Precise Frequency and Bandwidth Control

     Brito Brito, Zabdiel; Llamas Garro, Ignacio; Pradell Cara, Lluis; Alonso, Corona
    European Microwave Conference 2008
    Presentation of work at congresses

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