Creat membership Creat membership
Sign in

Forgot password?

Confirm
  • Forgot password?
    Sign Up
  • Confirm
    Sign In
home > search

Now showing items 1 - 16 of 74

  • An X-Band Doppler Motion Sensor With a Two-Ports

    Kim, Young-Gi   Dam, Hyoun-Kyou   Lee, Jin-Woo   Bae, Jung-Hyung   Hwang, Jae-Yeon   Kim, Hyun-Jin   Roblin, Patrick   Kim, Chang-Woo  

    In this paper, we propose an X-band Doppler motion sensor based on a high-efficiency dual-output oscillator circuit integrated with a common resonator and a passive mixer. The oscillator provides two output signals with different power levels. The oscillator and mixer circuits are implemented in a 0.5 mu m AlGaAs/InGaAs depletion-mode pseudomorphic high electronic mobility transistor process. The oscillator shows a high output power of 21.15 dBm at 11.2 GHz and a peak efficiency of 41.1 % at 10.7 GHz. For a 10.3 GHz oscillation, a phase noise of -132 dBc/Hz is obtained at a 10 MHz offset. The output power centered at 10.58 GHz is 11.67 dBm at one port and 9.12 dBm at the other port, and a phase noise of -105.8 dBc/Hz at 1 MHz offset when providing a 2.55 V supply with 28 mA consumption for practical Doppler motion sensor application that detects human motion at a distance of 13 m. A detection range of 30 m has been proven for human motion. This paper demonstrates the feasibility of a compact high efficiency Doppler motion sensor without a bulky power divider or amplifier by monolithic combining the proposed oscillator and mixer circuit.
    Download Collect
  • IMS2020 Microwave Week Workshops

    Wang, Ethan   Heydari, Payam   Dunworth, Jeremy   Manstretta, Danilo   Hella, Mona   Roblin, Patrick  

    Presents information on the IMS 2020 Conference.
    Download Collect
  • Optimal Definition of Class F for Realistic Transistor Models

    Martinez-Rodriguez, Francisco J.   Roblin, Patrick   Popovic, Zoya   Martinez-Lopez, Jose I.  

    An optimal three-harmonic definition of class F at the intrinsic level is presented for realistic transistor models exhibiting IV characteristics with a nonzero knee voltage. This updated class-F definition is needed for use with the recently reported embedding device model, which predicts in a single harmonic balance simulation the voltage and current waveforms required at the package reference planes to sustain an intrinsic mode of operation. Optimal class-F operation is obtained by setting to infinite the third-harmonic output impedance of the transistor IV characteristics instead of using an open load for the third-harmonic termination. This is achieved by fine tuning the class-F quasi-rectangular drain voltage waveform. The required third-harmonic component of the drain voltage in the optimal class F is then found to be generated by the lossless inductive termination of the third-harmonic component of the drain displacement current arising from the nonlinear drain-to-source capacitance. The proposed class-F definition is verified for a gallium nitride (GaN) high electron mobility transistor using third-harmonic load-pull simulations with a realistic GaN transistor model. The optimal third-harmonic load termination predicted using the class-F definition is found to be in full agreement with the one obtained from the drain efficiency contour plots. A close agreement is also obtained for the predicted and measured optimal third-harmonic load termination, bringing experimental support for the proposed class-F definition.
    Download Collect
  • RF Front-End Flexibility, Self-Calibration, and Self-Linearization

    Roblin, Patrick   Rawat, Meenakshi   Ratnasamy, Varun  

    Download Collect
  • Continuous Class-B/J Power Amplifier Using a Nonlinear Embedding Technique

    Saxena, Samarth   Rawat, Karun   Roblin, Patrick  

    This brief explores the design space for realizable solution of a broadband class-B/J continuous mode of power amplifier (PA). The PA is initially designed at the current-source reference plane with the correct voltage and current waveforms. The intrinsic impedances are then projected to the package reference plane using the model-based nonlinear-embedding technique. An insight is provided into engineering the extrinsic harmonic impedance to rotate clockwise on the Smith chart to be able to match it using a Foster circuit. It is concluded that decreasing the empirical parameter a of a general class-B/J voltage equation with increasing frequency leads to a clockwise trajectory on the Smith chart of the second harmonic at the package plane. In order to validate the advantage of this analysis, the PA is implemented using a 15 W gallium nitride high electron mobility transistor in the frequency range of 1.3 to 2.4 GHz and drain efficiency between 63% and 72% in measurement was achieved over the entire bandwidth.
    Download Collect
  • Guest Editorial

    Rafael-Valdivia, Guillermo   Roblin, Patrick  

    Download Collect
  • Investigating Continuous Class-F Power Amplifier Using Nonlinear Embedding Model

    Aggrawal, Ekta   Rawat, Karun   Roblin, Patrick  

    This letter investigates the design space for feasible load impedances of broadband continuous class-F power amplifier (PA) using the nonlinear embedding transfer function. This can overcome the limitation of anticlockwise trajectory of second-harmonic impedance on Smith chart. The approach starts with the design at intrinsic plane based on generic representation of drain voltage and current waveforms. Nonlinear embedding transfer network is then used to project intrinsic loads to the package plane. The proposed design strategy is verified with the implementation of a 15-W GaN HEMT-based PA operating over the frequency range of 1.5 to 2.5 GHz with drain efficiency between 60%-75%. This corresponds to the fractional bandwidth of 50%.
    Download Collect
  • On the design of GaN Chireix power amplifiers using an embedding device model

    Roblin, Patrick   Chang, Hsiu-Chen   Martinez-Rodriguez, Francisco J.   Xie, Chenggang   Martinez-Lopez, Jose I.  

    As wireless cellular communication keeps expanding toward higher bandwidth, multiband signals, and high frequencies of operation, the design of power efficient radio frequency power amplifiers (PAs) for cellular phone basestations is submitted to more stringent requirements. This paper discusses the promising technique of nonlinear embedding, which may help stream line the design of such PAs. To this order, the design of a GaN radio frequency PA from device modeling to circuit design is presented. The large signal modeling of GaN high-electron-mobility transistorsincluding thermal and trapping memory effects is discussed first. The nonlinear embedding device model is then introduced using the concept of an anti-circuit transfer network. This embedding device model is then applied to the design of a Chireix amplifier. New Chireix design equations are developed to work with the memoryless inner core of the embedding device model, and their validity is confirmed in circuit simulations. The Chireix amplifier is then designed using the multi-harmonic impedance terminations predicted by the embedding device model for the package reference planes. Finally, the resulting Chireix amplifier is implemented in a circuit simulator with the original GaN high-electron-mobility transistors device model and verified in simulations to have a performance approaching that of the originally targeted Chireix at the current reference planes. These theoretical and simulation results demonstrate the potential of the nonlinear embedding PA design technique in the design of Chireix power amplifiers. Copyright (c) 2016 John Wiley & Sons, Ltd.
    Download Collect
  • New Mixed-Mode Design Methodology for High-Efficiency Outphasing Chireix Amplifiers

    Chang, Hsiu-Chen   Hahn, Yunsik   Roblin, Patrick   Barton, Taylor Wallis  

    A new design methodology providing optimal mixed-mode operation for dual-input class-F outphasing Chireix amplifiers is presented. The design starts with single-transistor class-F simulations at the intrinsic I-V reference planes to directly select the optimal peak and backoff resistive loads R-min and R-max and input RF gate drives yielding the best combination of efficiencies and output powers without needing to perform a load pull simulation or measurement. New analytic equations expressed only in terms of R-min and R-max are given for designing the Chireix combiner at the current source reference planes. Nonlinear embedding is then used to predict the incident power and multi-harmonic source and load impedances required at the package reference planes to physically implement the power amplifier (PA). An analytic formula solely expressed in terms of R-min and R-max is reported for the peak and backoff outphasing angles required at the PA input reference planes. A Chireix outphasing PA is designed using two 15-W GaN HEMTs. A Chireix outphasing PA exhibits a peak efficiency of 72.58% with peak power of 43.97 dBm and a 8-dB backoff efficiency of 75.22% at 1.9 GHz. Measurements with 10-MHz LTE signals with 9.6-dB PAPR yield 59.4% average drain efficiency at 1.9 GHz while satisfying the 3GPP linearity requirements.
    Download Collect
  • New Mixed-Mode Design Methodology for High-Efficiency Outphasing Chireix Amplifiers

    Chang, Hsiu-Chen   Hahn, Yunsik   Roblin, Patrick   Barton, Taylor Wallis  

    Download Collect
  • Concurrent Linearization

    Roblin, Patrick   Quindroit, Christophe   Naraharisetti, Naveen   Gheitanchi, Shahin   Fitton, Mike  

    Download Collect
  • On the design of GaN Chireix power amplifiers using an embedding device model

    Roblin, Patrick   Chang, Hsiu-Chen   Martinez-Rodriguez, Francisco J.   Xie, Chenggang   Martinez-Lopez, Jose I.  

    Download Collect
  • Asymmetric Doherty Power Amplifier Designed Using Model-Based Nonlinear Embedding

    Jang, Haedong   Roblin, Patrick   Quindroit, Christophe   Lin, Yiqiao   Pond, Robert D.  

    A novel procedure is introduced for designing Doherty amplifiers using the model-based nonlinear-embedding technique. First, the Doherty intrinsic load-matching network is designed at the transistor current-source reference plane with the main and auxiliary devices interconnected. Identical devices with different biasing are used for realizing an asymmetric Doherty implementation with 9-dB back-off. The required multiharmonic impedances at the package planes are then obtained using the embedding device model for both devices, and the complex load impedance at the fundamental is projected back to resistive loads using an offset line. An even-number multisection impedance transformer and a reduced drain voltage of the main amplifier are used to design the asymmetric Doherty load network while providing the necessary loads to the main and auxiliary devices. The optimization of the drain efficiency and gain curves of the asymmetric Doherty operation for the proposed design is further investigated by adjusting the auxiliary gate-bias. An efficiency above 50% over an 11-dB power range is experimentally observed with 41.8-dBm peak output power using continuous wave (CW) at 2 GHz. Using a dual-input implementation of the designed Doherty power amplifier (PA), a systematic dual-input CW characterization of the Doherty operation is performed to establish the relative auxiliary-to-main phase offsets and power offsets yielding a maximum efficiency under constant gain. From this dual-input characterization, it is found that the optimal gate bias for single-input Doherty operation is the one for which the constant-gain maximum efficiency is achieved for a quasi-constant auxiliary-to-main input power ratio corresponding to the one implemented in the input divider in the single-input Doherty PA.
    Download Collect
  • Guest Editorial Special Issue on Emerging RF Measurement Techniques and Applications

    ROBLIN, PATRICK   LI, CHANGZHI   HAYDEN, LEONARD  

    Download Collect
  • NVNA Techniques for Pulsed RF Measurements

    Roblin, Patrick   Ko, Young   Yang, Chieh   Suh, Inwon   Doo, Seok  

    Download Collect
  • NVNA Techniques for Pulsed RF Measurements

    Roblin, Patrick   Ko, Young Seo   Yang, Chieh Kai   Suh, Inwon   Doo, Seok Joo  

    Download Collect
1 2 3 4 5

Contact

If you have any feedback, Please follow the official account to submit feedback.

Turn on your phone and scan

Submit Feedback