The Experts below are selected from a list of 279 Experts worldwide ranked by ideXlab platform

Binboga Siddik Yarman - One of the best experts on this subject based on the ideXlab platform.

  • Broadband RF and Microwave amplifier design employing real-frequency techniques
    Radio Frequency and Microwave Power Amplifiers. Volume 1: Principles Device Modeling and Matching Networks, 2019
    Co-Authors: Binboga Siddik Yarman
    Abstract:

    The Chapter introduces novel techniques to design wideband Amplifiers employing “real-frequency techniques" (RFTs). In essence, RFTs are wideband semi-analytic design methods to realize lossless matching networks and real frequency (RF) and Microwave Amplifiers with optimum circuit topologies. After an introductory section, the Chapter discusses: a simplified real-frequency technique (SRFT) to design Microwave Amplifiers, a SRFT single-stage Microwave amplifier design algorithm, amplifier stability, design practical aspects, ultra-wideband Microwave amplifier design using commensurate transmission lines, characteristic impedances physical realization, characteristic impedance calculations, an algorithm for broadband multistage Microwave Amplifiers design via SRFTstep-by-step multistage amplifier design, a Microwave power amplifier with mixed lumped and distributed elements design.

  • On numerical design technique of wideband Microwave Amplifiers based on GaN small-signal device model
    Analog Integrated Circuits and Signal Processing, 2014
    Co-Authors: Ramazan Köprü, Hakan Kuntman, Binboga Siddik Yarman
    Abstract:

    This work presents an application of Normalized Gain Function (NGF) method to the design of linear wideband Microwave Amplifiers based on small-signal model of a device. NGF has been originally developed to be used together with an S-parameter (*.s2p) file, whereas this work enables the NGF to be able to work with explicit S-parameter formulae derived from the small-signal model of the device. This approach provides the designer to be able to use simple set of S-parameter equations instead of S-parameter file of the device. Representation of the device simply by several model equations not only eliminates the need of carrying large number of data but also provides the capability of equation-based easy, realistic and equispaced S-parameter data generation in any desired resolution in frequency axis without requiring interpolation. NGF is defined as the ratio of T and |S_21|^2, i.e. T_N = T/|S_21|^2, gain function of the amplifier to be designed and transistor forward gain function, respectively. Synthesis of output/input matching networks (OMN/IMN) of the amplifier requires two target gain functions in terms of T_N, to be used in two sequential non-linear optimization procedures, respectively. An amplifier with a flat gain of ~10 dB operating in 0.8–2.35 GHz is designed using a small-signal model of an experimental GaN-HEMT. Theoretical amplifier performance obtained in Matlab is shown to be in excellent agreement with the simulated performance in MWO (Microwave Office, AWR Inc.). A prototype low-power amplifier having a ~10 to 12 dB gain, operating in (0.9–1.5 GHz) is also produced and measured which yielded good performance results.

  • ISCAS (4) - Microwave amplifier design for mobile communication via immittance data modelling
    Proceedings of the 2003 International Symposium on Circuits and Systems 2003. ISCAS '03., 2003
    Co-Authors: A. Kilinc, Binboga Siddik Yarman, H. Pinarbasi, Ahmet Aksen
    Abstract:

    In this paper, a practical broadband Microwave amplifier design algorithm based on immittance data modelling is presented. In the course of design, first, the optimum input and output terminations for the active device are produced employing the real frequency technique. Then, these terminations are modelled utilizing the new immittance-modeling tool to synthesize the front-end and back-end matching networks. An example is included to exhibit the implementation of the proposed design algorithm to construct a single stage wideband Microwave amplifier over a wide frequency band. It is expected that the proposed design algorithm will find applications in the design of Microwave Amplifiers on MMIC for mobile communication.

  • A broadband Microwave amplifier design by means of immittance based data modelling tool
    IEEE AFRICON. 6th Africon Conference in Africa, 2002
    Co-Authors: A. Kilinc, Metin Şengül, H. Pinarbas, Binboga Siddik Yarman
    Abstract:

    In this paper a practical broadband Microwave amplifier design algorithm is introduced utilizing the immittance data-modelling tool. In the course of design, first, the optimum input and output terminations for the active device are produced employing the real frequency technique. Then, these terminations are modelled utilizing the new immittance-modelling tool to synthesize the front-end and back-end matching networks. An example is included to exhibit the implementation of the proposed design algorithm to construct a single stage BJT amplifier over a wide frequency band. It is expected that the proposed design algorithm will rind applications to realize wideband Microwave Amplifiers put on MMIC for mobile communication.

Juan-mari Collantes - One of the best experts on this subject based on the ideXlab platform.

  • Experimental Characterization of Stability Margins in Microwave Amplifiers
    IEEE Transactions on Microwave Theory and Techniques, 2012
    Co-Authors: N. Otegi, A. Anakabe, Juan-mari Collantes, Joana Pelaz, Geoffroy Soubercaze-pun
    Abstract:

    This paper proposes a method for the experimental estimation of the stability margins in Microwave Amplifiers. The approach is based on measuring a closed-loop frequency response representing the linearization of the circuit about a steady-state solution. Critical poles of the amplifier are then obtained by applying conventional pole-zero identification techniques to the measured frequency response. As circuit parameters are modified, the evolution of these critical poles on the complex plane provides a practical way to assess the robustness of the design regarding its stability. Two types of common instabilities in Microwave Amplifiers are studied: low-frequency bias oscillations and parametric oscillations. For the low-frequency oscillations, the approach proposes the inclusion of an observation RF port into the amplifier bias path to experimentally obtain the critical poles of the circuit from a reflection coefficient measurement. Pole-placement techniques are then applied to increase the stability margin of detected critical resonances. For the parametric oscillations, pole-zero identification is applied to a frequency response obtained from a mixer-like characterization equivalent to the measurement of a “hot” reflection coefficient. The methodology is applied to two amplifier prototypes: an L-band field-effect transistor amplifier and a dual-mode WiFi-WIMAX amplifier that exhibit different kinds of unstable behavior.

  • Increasing low-frequency stability margins in Microwave Amplifiers from experimental data
    2012 IEEE MTT-S International Microwave Symposium Digest, 2012
    Co-Authors: N. Otegi, A. Anakabe, Juan-mari Collantes, Joana Pelaz, Geoffroy Soubercaze-pun
    Abstract:

    A key aspect in the robust design of Microwave Amplifiers is to ensure circuit stability beyond the nominal operating conditions. In this work, a method for measuring and controlling the stability margin of low-frequency resonances in Microwave Amplifiers is proposed. The approach adds an extra RF port in series with an R-C stabilization network that is connected to the amplifier bias path. The extra RF port is used to experimentally obtain the critical poles of the circuit. Then, from the obtained pole-zero map, pole-placement techniques are applied to get the R-C values that increase the stability margin of the critical resonances. In this way, the risk of running into a low frequency oscillation when amplifier conditions are varied can be significantly reduced. The complete approach is experimentally validated in a demonstrator prototype built in printed circuit board technology.

  • monte carlo stability analysis of Microwave Amplifiers
    Wireless and Microwave Technology Conference, 2011
    Co-Authors: Juan-mari Collantes, A. Anakabe, N. Otegi, N Ayllon, A Mallet, Geoffroy Soubercazepun
    Abstract:

    Pole-zero identification is being increasingly used as a method to analyze the stability of Microwave circuits. However, in its current form, the stability analysis through pole-zero identification relies on a quality assessment that is based on visual inspection. This implies a manual approach that limits in practice the handling of a large amount of data as in the case of a yield or sensitivity analysis. Here, an automated methodology based on pole-zero identification is applied to the stability evaluation in the context of a Monte-Carlo analysis. The methodology is based on an algorithm that prevents the adverse effects due to undermodeling and overmodeling on the stability criteria. The approach is illustrated through its application to two in-home built amplifier prototypes: a medium power band L FET amplifier exhibiting a low frequency oscillation and a SiGe HBT reconfigurable amplifier for Wifi/Wimax applications that shows an undesired frequency division for some particular input drive conditions.

  • Closed-loop stability analysis of Microwave Amplifiers
    Electronics Letters, 2001
    Co-Authors: Josu Jugo, Joaquin Portilla, A. Anakabe, Almudena Suarez, Juan-mari Collantes
    Abstract:

    A stability analysis technique of Microwave Amplifiers, valid for large- or small-signal regimes, is presented. The technique calculates the system poles and zeroes from a closed-loop frequency response of the circuit linearised around its steady state. The method has been applied to an S-band monolithic amplifier, detecting spurious oscillations for certain specific bias conditions and input power levels, in good agreement with measurements.

A. Anakabe - One of the best experts on this subject based on the ideXlab platform.

  • Experimental Characterization of Stability Margins in Microwave Amplifiers
    IEEE Transactions on Microwave Theory and Techniques, 2012
    Co-Authors: N. Otegi, A. Anakabe, Juan-mari Collantes, Joana Pelaz, Geoffroy Soubercaze-pun
    Abstract:

    This paper proposes a method for the experimental estimation of the stability margins in Microwave Amplifiers. The approach is based on measuring a closed-loop frequency response representing the linearization of the circuit about a steady-state solution. Critical poles of the amplifier are then obtained by applying conventional pole-zero identification techniques to the measured frequency response. As circuit parameters are modified, the evolution of these critical poles on the complex plane provides a practical way to assess the robustness of the design regarding its stability. Two types of common instabilities in Microwave Amplifiers are studied: low-frequency bias oscillations and parametric oscillations. For the low-frequency oscillations, the approach proposes the inclusion of an observation RF port into the amplifier bias path to experimentally obtain the critical poles of the circuit from a reflection coefficient measurement. Pole-placement techniques are then applied to increase the stability margin of detected critical resonances. For the parametric oscillations, pole-zero identification is applied to a frequency response obtained from a mixer-like characterization equivalent to the measurement of a “hot” reflection coefficient. The methodology is applied to two amplifier prototypes: an L-band field-effect transistor amplifier and a dual-mode WiFi-WIMAX amplifier that exhibit different kinds of unstable behavior.

  • Increasing low-frequency stability margins in Microwave Amplifiers from experimental data
    2012 IEEE MTT-S International Microwave Symposium Digest, 2012
    Co-Authors: N. Otegi, A. Anakabe, Juan-mari Collantes, Joana Pelaz, Geoffroy Soubercaze-pun
    Abstract:

    A key aspect in the robust design of Microwave Amplifiers is to ensure circuit stability beyond the nominal operating conditions. In this work, a method for measuring and controlling the stability margin of low-frequency resonances in Microwave Amplifiers is proposed. The approach adds an extra RF port in series with an R-C stabilization network that is connected to the amplifier bias path. The extra RF port is used to experimentally obtain the critical poles of the circuit. Then, from the obtained pole-zero map, pole-placement techniques are applied to get the R-C values that increase the stability margin of the critical resonances. In this way, the risk of running into a low frequency oscillation when amplifier conditions are varied can be significantly reduced. The complete approach is experimentally validated in a demonstrator prototype built in printed circuit board technology.

  • monte carlo stability analysis of Microwave Amplifiers
    Wireless and Microwave Technology Conference, 2011
    Co-Authors: Juan-mari Collantes, A. Anakabe, N. Otegi, N Ayllon, A Mallet, Geoffroy Soubercazepun
    Abstract:

    Pole-zero identification is being increasingly used as a method to analyze the stability of Microwave circuits. However, in its current form, the stability analysis through pole-zero identification relies on a quality assessment that is based on visual inspection. This implies a manual approach that limits in practice the handling of a large amount of data as in the case of a yield or sensitivity analysis. Here, an automated methodology based on pole-zero identification is applied to the stability evaluation in the context of a Monte-Carlo analysis. The methodology is based on an algorithm that prevents the adverse effects due to undermodeling and overmodeling on the stability criteria. The approach is illustrated through its application to two in-home built amplifier prototypes: a medium power band L FET amplifier exhibiting a low frequency oscillation and a SiGe HBT reconfigurable amplifier for Wifi/Wimax applications that shows an undesired frequency division for some particular input drive conditions.

  • Closed-loop stability analysis of Microwave Amplifiers
    Electronics Letters, 2001
    Co-Authors: Josu Jugo, Joaquin Portilla, A. Anakabe, Almudena Suarez, Juan-mari Collantes
    Abstract:

    A stability analysis technique of Microwave Amplifiers, valid for large- or small-signal regimes, is presented. The technique calculates the system poles and zeroes from a closed-loop frequency response of the circuit linearised around its steady state. The method has been applied to an S-band monolithic amplifier, detecting spurious oscillations for certain specific bias conditions and input power levels, in good agreement with measurements.

N. Otegi - One of the best experts on this subject based on the ideXlab platform.

  • Experimental Characterization of Stability Margins in Microwave Amplifiers
    IEEE Transactions on Microwave Theory and Techniques, 2012
    Co-Authors: N. Otegi, A. Anakabe, Juan-mari Collantes, Joana Pelaz, Geoffroy Soubercaze-pun
    Abstract:

    This paper proposes a method for the experimental estimation of the stability margins in Microwave Amplifiers. The approach is based on measuring a closed-loop frequency response representing the linearization of the circuit about a steady-state solution. Critical poles of the amplifier are then obtained by applying conventional pole-zero identification techniques to the measured frequency response. As circuit parameters are modified, the evolution of these critical poles on the complex plane provides a practical way to assess the robustness of the design regarding its stability. Two types of common instabilities in Microwave Amplifiers are studied: low-frequency bias oscillations and parametric oscillations. For the low-frequency oscillations, the approach proposes the inclusion of an observation RF port into the amplifier bias path to experimentally obtain the critical poles of the circuit from a reflection coefficient measurement. Pole-placement techniques are then applied to increase the stability margin of detected critical resonances. For the parametric oscillations, pole-zero identification is applied to a frequency response obtained from a mixer-like characterization equivalent to the measurement of a “hot” reflection coefficient. The methodology is applied to two amplifier prototypes: an L-band field-effect transistor amplifier and a dual-mode WiFi-WIMAX amplifier that exhibit different kinds of unstable behavior.

  • Increasing low-frequency stability margins in Microwave Amplifiers from experimental data
    2012 IEEE MTT-S International Microwave Symposium Digest, 2012
    Co-Authors: N. Otegi, A. Anakabe, Juan-mari Collantes, Joana Pelaz, Geoffroy Soubercaze-pun
    Abstract:

    A key aspect in the robust design of Microwave Amplifiers is to ensure circuit stability beyond the nominal operating conditions. In this work, a method for measuring and controlling the stability margin of low-frequency resonances in Microwave Amplifiers is proposed. The approach adds an extra RF port in series with an R-C stabilization network that is connected to the amplifier bias path. The extra RF port is used to experimentally obtain the critical poles of the circuit. Then, from the obtained pole-zero map, pole-placement techniques are applied to get the R-C values that increase the stability margin of the critical resonances. In this way, the risk of running into a low frequency oscillation when amplifier conditions are varied can be significantly reduced. The complete approach is experimentally validated in a demonstrator prototype built in printed circuit board technology.

  • monte carlo stability analysis of Microwave Amplifiers
    Wireless and Microwave Technology Conference, 2011
    Co-Authors: Juan-mari Collantes, A. Anakabe, N. Otegi, N Ayllon, A Mallet, Geoffroy Soubercazepun
    Abstract:

    Pole-zero identification is being increasingly used as a method to analyze the stability of Microwave circuits. However, in its current form, the stability analysis through pole-zero identification relies on a quality assessment that is based on visual inspection. This implies a manual approach that limits in practice the handling of a large amount of data as in the case of a yield or sensitivity analysis. Here, an automated methodology based on pole-zero identification is applied to the stability evaluation in the context of a Monte-Carlo analysis. The methodology is based on an algorithm that prevents the adverse effects due to undermodeling and overmodeling on the stability criteria. The approach is illustrated through its application to two in-home built amplifier prototypes: a medium power band L FET amplifier exhibiting a low frequency oscillation and a SiGe HBT reconfigurable amplifier for Wifi/Wimax applications that shows an undesired frequency division for some particular input drive conditions.

Geoffroy Soubercaze-pun - One of the best experts on this subject based on the ideXlab platform.

  • Experimental Characterization of Stability Margins in Microwave Amplifiers
    IEEE Transactions on Microwave Theory and Techniques, 2012
    Co-Authors: N. Otegi, A. Anakabe, Juan-mari Collantes, Joana Pelaz, Geoffroy Soubercaze-pun
    Abstract:

    This paper proposes a method for the experimental estimation of the stability margins in Microwave Amplifiers. The approach is based on measuring a closed-loop frequency response representing the linearization of the circuit about a steady-state solution. Critical poles of the amplifier are then obtained by applying conventional pole-zero identification techniques to the measured frequency response. As circuit parameters are modified, the evolution of these critical poles on the complex plane provides a practical way to assess the robustness of the design regarding its stability. Two types of common instabilities in Microwave Amplifiers are studied: low-frequency bias oscillations and parametric oscillations. For the low-frequency oscillations, the approach proposes the inclusion of an observation RF port into the amplifier bias path to experimentally obtain the critical poles of the circuit from a reflection coefficient measurement. Pole-placement techniques are then applied to increase the stability margin of detected critical resonances. For the parametric oscillations, pole-zero identification is applied to a frequency response obtained from a mixer-like characterization equivalent to the measurement of a “hot” reflection coefficient. The methodology is applied to two amplifier prototypes: an L-band field-effect transistor amplifier and a dual-mode WiFi-WIMAX amplifier that exhibit different kinds of unstable behavior.

  • Increasing low-frequency stability margins in Microwave Amplifiers from experimental data
    2012 IEEE MTT-S International Microwave Symposium Digest, 2012
    Co-Authors: N. Otegi, A. Anakabe, Juan-mari Collantes, Joana Pelaz, Geoffroy Soubercaze-pun
    Abstract:

    A key aspect in the robust design of Microwave Amplifiers is to ensure circuit stability beyond the nominal operating conditions. In this work, a method for measuring and controlling the stability margin of low-frequency resonances in Microwave Amplifiers is proposed. The approach adds an extra RF port in series with an R-C stabilization network that is connected to the amplifier bias path. The extra RF port is used to experimentally obtain the critical poles of the circuit. Then, from the obtained pole-zero map, pole-placement techniques are applied to get the R-C values that increase the stability margin of the critical resonances. In this way, the risk of running into a low frequency oscillation when amplifier conditions are varied can be significantly reduced. The complete approach is experimentally validated in a demonstrator prototype built in printed circuit board technology.