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3.3
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30 Apr 2012
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B
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07 Aug 2012
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A
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30 Apr 2012
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C
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30 Apr 2012
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A
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30 Apr 2012
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by R. M. Smith, J. Lees, P. J. Tasker, J. Benedikt and S. C. Cripps
A high-efficiency push-pull power amplifier has been designed and measured across a bandwidth of 250MHz to 3.1GHz. The output power was 46dBm with a drain efficiency of above 45% between 700MHz and 2GHz, with a minimum output power of 43dBm across the entire band. In addition, a minimum of 60% drain efficiency and 11dB transducer gain was measured between 350MHz and 1GHz. The design was realized using a coaxial cable transmission line balun, which provides a broadband 2:1 impedance transformation ratio and reduces the need for bandwidth-limiting conventional matching. The combination of output power, bandwidth and efficiency are believed to be the best reported to date at these frequencies.
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Design
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01 Jun 2012
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by Andrei Grebennikov
In this paper, a novel high-efficiency four-stage Doherty power amplifier architecture convenient for practical implementation in base station applications for modern communication standards has been proposed and fabricated.
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Design
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01 Apr 2011
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by Marco J. Pelk, W. C. Edmund Neo, John R. Gajadharsing, Raymond S. Pengelly, Leo C. N. de Vreede
A three-way Doherty 100-W GaN base-station power amplifier at 2.14 GHz is presented.
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Design
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15 May 2008
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by Sheikh Nijam Ali, Thomas Johnson
A new architecture for RF switch-mode power amplifiers is proposed. In this design, a pulse encoded signal switches a single RF power device with a broadband output match coupled to an output diplexer. The broadband termination impedance across the device minimizes switching losses.
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Design
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01 Apr 2012
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by Raymond S. Pengelly, Simon M. Wood, James W. Milligan, Scott T. Sheppard, and William L. Pribble
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Design
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01 Jun 2012
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by Raymond S. Pengelly, Brad Millon, Donald Farrell, Bill Pribble, and Simon Wood
Presentation from the 2008 IEEE MTT-S International Microwave Symposium (IMS) Workshop on Challenges in Model-Based HPA Design
This presentation discusses attributes of GaN HEMTs, Cree GaN HEMT models, design examples (Broadband CW Amplifiers and Linear WiMAX Amplifier), and future model improvements.
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Design
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16 Jun 2008
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by Kenle Chen, Xiaoguang Liu, William J. Chappell and Dimitrios Peroulis
A unique GaN power amplifier (PA) with an integrated evanescent-mode resonator as its output matching network is presented in this paper.
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Design
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01 Jun 2011
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by Sang Hoon Kim, Hyoung Jong Kim, Suk Woo Shin, Jae Duk Kim, Bo Ki Kim and Jin Joo Choi
This paper proposes a new configuration for power oscillator based on the combined power amplifier. The focus is on power combining as a oscillator structure with a positive feedback loop line. The proposed configuration consists of a harmonic-tuned combined power amplifier using two Gallium Nitride High Electron Mobility Transistors (CGH40025), 3dB Wilkinson divider/combiner, a directional coupler, an isolator, a coaxial line and mechanical phase shifters.
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Design
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01 Jun 2011
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by Kenle Chen and Dimitrios Peroulis
This paper presents a novel adaptive power amplier (PA) architecture for performing dynamic-load-modulation. For the rst time, a dynamically-load-modulated PA design that achieves octave bandwidth, high power and high efciency simultaneously is experimentally demonstrated. This PA design is based on a commercial GaN HEMT.
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Design
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01 Jun 2012
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by Robert Smith; Professor Steve C. Cripps
Using differential linear measurements, the harmonic impedance conditions presented by simple transmission line baluns are identified. These impedances are shown to differ significantly from the harmonic conditions usually associated with push-pull amplifiers. When taking into account these impedance conditions, a family of waveforms corresponding to the theoretical waveforms inside a push-pull amplifier can be described mathematically and measured using a harmonic load-pull system.
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Design
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01 Apr 2012
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by Robert Smith; Professor Steve C. Cripps
Using differential linear measurements, the harmonic impedance conditions presented by simple transmission line baluns are identified. These impedances are shown to differ significantly from the harmonic conditions usually associated with push-pull amplifiers. When taking into account these impedance conditions, a family of waveforms corresponding to the theoretical waveforms inside a push-pull amplifier can be described mathematically and measured using a harmonic load-pull system.
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Design
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01 Apr 2012
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by Kenle Chen, Dimitrios Peroulis
A new methodology for designing and implementing high-efficiency broadband Class-E power amplifiers (PAs) using high-order low-pass filter-prototype is proposed in this paper. A GaN transistor is used in this work, which is carefully modeled and characterized to prescribe the optimal output impedance for the broadband Class-E operation.
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Design
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01 Apr 2012
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by Andrei Grebennikov
In modern wireless communication systems such as CDMA2000, WCDMA, or OFDM with increased bandwidth and high data rate, the transmit signal is characterized by a high peak-to-average power ratio (PAR) due to wide and rapid variations of the instantaneous transmit power.
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Design
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01 Feb 2012
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by Z. Yusoff, J. Lees, J. Benedikt, P. J. Tasker, S.C. Cripps
A new technique called Auxiliary Envelope Tracking (AET) is proposed, which demonstrates substantial improvement in linearity of RF power amplifiers.
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Design
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01 Jun 2011
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by Nicolas Le Gallou, David Sardin, Christophe Delepaut, Michel Campovecchio, Stéphane Rochette
This paper describes a fast envelope-tracking circuit capable of 10 MHz (up to 17.5 MHz) bandwidth based on RF GaN switching devices and 50 MHz switching frequency.
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Design
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01 Jun 2011
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by Donald A. Gajewski, Scott Sheppard, Tina McNulty, Jeff B. Barner, Jim Milligan and John Palmour
This paper reports the reliability performance of the Cree, Inc., GaN/AlGaN HEMT MMIC process technology, fabricated on 100 mm high purity semi-insulating (HPSI) 4H-SiC substrates.
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Design
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01 May 2011
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by Ildu Kim, Jangheon Kim, Junghwan Moon, Jungjoon Kim, and Bumman Kim
Demonstrating a highly efficient Hybrid Envelope Elimination and Restoration transmitter for IEEE 802.16e Mobile WiMAX applications using a highly efficient saturated Power Amplifier (PA). For the optimum H-EER operation, the PA has been designed to have a maximum PAE at the average Vds region by using 10 W (P3dB ) GaN High Electron Mobility Transistor.
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Design
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01 Jun 2009
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