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Excel file
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2
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22 Mar 2011
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by Junghwan Son, Ildu Kim, Junghwan Moon, Juyeon Lee, Bummam Kim
An asymmetric Doherty Power Amplifier (ADPA) is introduced using a new output combining circuit for easy of implementation with a large matching tolerance. The proposed APDA has been implemented using GaN HEMT devices at 2.6 GHz for WiMAX signal with 5MHz bandwidth and 8.3 dB peak to average power ratio.
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Design
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by Guolin Sun, Rolf H. Jansen
A comprehensive method of designing a broadband Doherty power amplifier is presented in this paper. The essential limitations of bandwidth extension of a Doherty power amplifier are discussed based on the proposed structure of the Doherty power amplifier, which also takes the output matching networks of both sub-amplifiers into account. The broadband matching is realized by applying the simplified real frequency technique with the desired frequency dependent optimum impedances. GaN transistors were selected to implement the circuit structure.
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Design
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by Junghwan Moon, Juyeon Lee, Bumman Kim, Raymond S. Pengelly, Ryan Baker
The Seventh Student High-Efficiency Power Amplifier (PA) Design Competition was held at the IEEE Microwave Theory and Techniques Society (MTT-S) International Microwave Symposium (IMS) 2011 in Baltimore, Maryland. Every year, many students from all over the world participate in the competition and demonstrate their ability to design a high-efficiency PA.
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Article
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01 Feb 2012
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by Woo Lee, Sang-Ho Kam, and Yoon-Ha Jeong
This paper describes a new three-stage Doherty power amplifier (DPA) with an adaptive driving amplifier inserted at the input of the carrier cell.
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Design
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01 Jun 2011
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by Zachary D. Schwartz and George E. Ponchak
A SiC Clapp oscillator fabricated on an alumina substrate with chip capacitors and spiral inductors is designed for high temperature operation at 1 GHz. The oscillator operated from 30 to 200 ºC with an output power of 21.8 dBm at 1 GHz and 200 ºC. The efficiency at 200 ºC is 15 %. The frequency variation over the temperature range is less than 0.5 %.
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Article
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01 Nov 2005
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by Jorge Moreno Rubio, Jie Fang, R. Quaglia, V. Camarchia, M. Pirola, S. Donati Guerrieri, G. Ghione
The design, implementation and characterization of a Doherty Power Amplifier (DPA) for 3.5 GHz WiMAX applications are discussed. The DPA has been implemented using a commercial GaN HEMT from Cree inc., following a class AB and C scheme for the main and peak module, respectively.
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Design
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01 Apr 2011
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by Caroline W. Waiyaki
Report for US Army Research Laboratory. A key component of microwave telecommunication systems is the power amplifier (PA). The design parameters of a communication system, such as link performance, power budget, and thermal design are typically driven by the power amplifier’s linearity, output power, and efficiency.
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Design
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01 Sep 2010
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by L. Cabria, P. M. Cabral, J. C. Pedro, and J. A. García
This paper describes the design of a class E PA destined to be used as the final stage of a polar transmitter under IEEE 802.16e Mobile WiMAX signal excitation. Based on a 60 W GaN HEMT device, the load condition for optimum efficiency is set close to the maximum value of the power generating function for an OFDMA modulating signal.
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Design
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01 Feb 2010
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by Raymond S. Pengelly
This paper demonstrates the use of optimized analytical procedures to design lossy Class E amplifiers at 1 and 2 GHz using Si LDMOS FETs and SiC MESFETs respectively. The designs use new large-signal models for the LDMOS FETs and SiC MESFETs which provide accurate simulations in both deep sub-threshold (Class C) and fully RF driven "on" states.
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Design
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15 Apr 2004
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by David Schmelzer and Stephen I. Long
A Class F amplifier has been designed, fabricated, and tested using a GaN HEMT transistor and a hybrid PCB.
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Design
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12 Nov 2006
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by David Schmelzer and Stephen I. Long
A Class F amplifier has been designed, fabricated, and tested using a GaN HEMT transistor and hybrid printed circuit board (PCB) packaging.
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Design
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01 Oct 2007
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by Ellie Cijvat, Kevin Tom, Mike Faulkner, and Henrik Sjöland
This paper describes the design, simulation and measurement of a GaN power amplifier suitable for envelope and phase signal combination.
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Design
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01 Nov 2007
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by William L. Pribble, Jim M Milligan, and Raymond S. Pengelly
Abstract from the 2006 IEEE Topical Workshop on PAs for Wireless Communications (RWS)
Presentation from the 2006 IEEE Radio and Wireless Symposium in San Diego
A class-E power amplifier based on a GaN HEMT cell has been designed and tested.
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Design
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17 Jan 2006
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by William L. Pribble, Jim M Milligan, and Raymond S. Pengelly
Abstract from the 2006 IEEE Topical Workshop on PAs for Wireless Communications (RWS)
Presentation from the 2006 IEEE Radio and Wireless Symposium in San Diego
A class-E power amplifier based on a GaN HEMT cell has been designed and tested.
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Design
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17 Jan 2006
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by Ray Pengelly, Simon Wood, Jim Crescenzi
This article describes a WiMAX power amplifier, which achieves high performance using the latest device technologies and design techniques.
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Article
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01 Dec 2008
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by Simon M. Wood, Raymond S. Pengelly, William L. Pribble, Dustin E. Hoekstra
Abstract from the 2006 IEEE Topical Workshop on PAs for Wireless Communications (RWS)
Presentation from the 2006 IEEE Radio and Wireless Symposium in San Diego
This paper describes the results of a broadband, high linearity, high efficiency power amplifier for WiMAX basestation applications in the 3.3 - 3.9 GHz band.
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Design
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17 Jan 2006
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by Simon M. Wood, Raymond S. Pengelly, William L. Pribble, Dustin E. Hoekstra
Abstract from the 2006 IEEE Topical Workshop on PAs for Wireless Communications (RWS)
Presentation from the 2006 IEEE Radio and Wireless Symposium in San Diego
This paper describes the results of a broadband, high linearity, high efficiency power amplifier for WiMAX basestation applications in the 3.3 - 3.9 GHz band.
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Design
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17 Jan 2006
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by Bumjin Kim, D. Derickson, and C. Sun
A class B and a class F power amplifier are described using a GaN HEMT device.
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Design
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01 Dec 2007
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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 Philip A. Godoy, SungWon Chung, Taylor W. Barton, David J. Perreault, and Joel L. Dawson
A 1.95-GHz asymmetric multilevel outphasing (AMO) transmitter with class-E GaN power amplifiers (PAs) and discrete supply modulators is presented.
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Design
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01 Jun 2011
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by Junghwan Moon, Young Yun Woo, Bummam Kim
A novel design of the Doherty power amplifier (PA) to improve the efficiency at a back-off output power level.
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Design
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01 Sep 2009
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by Moon, Junghwan Son, Juyeon Lee, Jungjoon Kim, Seunghoon Jee, Seungchan Kim, and Bumman Kim
A multimode/multiband envelope tracking (ET) transmitter consisting of a hybrid switching amplifier (HSA) and a broadband saturated power amplifier (PA) is developed across 1.3 to 2.7 GHz.
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Design
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01 Jun 2011
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by Jangheon Kim, Junghwan Moon, Jungjoon Kim, Slim Boumaiza, and Bumman Kim
A novel design method without requiring the special harmonic termination circuit for a highly efficient power amplifier (PA) is proposed.
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Design
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01 Sep 2009
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by V. Carrubba, J. Lees, J. Benedikt, P. J. Tasker, S. C. Cripps
A novel, highly efficient and broadband RF power amplifier (PA) operating in “continuous class-F” mode has been realized for first time.
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Design
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01 Jun 2011
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by Jangheon Kim, Junghwan Moon, Bumman Kim, and Raymond S. Pengelly
This article presents the design of the winning PA with PAE of 73.2% at 3.2GHz operating frequency, which is equivalent to the weighted PAE performance of 97.9% by students from Pohang University of Science and Technology (POSTECH).
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Article
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01 Feb 2009
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by Yong-Sub Lee, Mun-Woo Lee, Sang-Ho Kam, and Yoon-Ha Jeong
This paper reports a new double Doherty power amplifier (DDPA) with a flat efficiency range, which consists of two-stage amplifiers.
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Design
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01 May 2010
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by Bumman Kim, Ildu Kim, Junghwan Moon
This article describes the design of a GaN Doherty power amplifier with digital pre-distortion as well as hybrid envelop elimination and restoration / envelop tracking technique (H-EER/ET).
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Article
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01 Aug 2010
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by Simon Wood, Carl Platis, Don Farrell, Brad Millon, Bill Pribble, Peter Smith, Ray Pengelly, and Jim Milligan
This article discusses various uses of Cree’s GaN HEMTs (CGH21120, CGH25120, CGH40120) in standard and novel amplifier topologies. It includes the practical use of Cree’s proprietary large signal models.
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Article
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01 May 2009
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by Ahmed Sayed, Stefan von der Mark and Georg Boeck
A 5-watt wideband power amplifier using a SiC MESFET has been designed. The frequency range covers 10 MHz to 2.4 GHz with small-signal gain of 8 dB. A broadband choke structure with a new technique was developed to obtain good isolation and low loss over the desired bandwidth. Input and output matching networks and shunt feedback topology were introduced to increase the bandwidth.
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Design
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12 Oct 2004
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by D. Kimball, J. Jeong, C. Hsia, P. Draxler, P. Asbeck, D. Choi, W. Pribble and R. Pengelly
Class E amplifiers offer significant advantages for high efficiency operation, although they have been largely limited to relatively low microwave frequencies and/or low output powers. GaN HFETs are well suited to Class E at high powers and high frequencies, inasmuch as their output capacitance is particularly low for a device with a given output power, and has little voltage dependence.
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Design
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17 Jan 2006
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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 Michael Boers
Michael Boers, Ph.D. Student, Wins IEEE MTT-S Power Amplifier Competition, 85% PAE Achieved with Microwave Office and Cree, Inc. GaN HEMT.
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Article
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01 Jul 2007
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by George Fischer
This paper focuses on how specific characteristics of wide band gap RF power transistors at device level map to benefits at architectural level with those frequency agile systems.
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Design
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15 Apr 2004
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by Caleb Fulton, William J. Chappell
This paper discusses the challenges of polarimetric phased array calibration, and demonstrates these techniques using a linear array of eight S-band dual-polarized antennas connected to an active Digital Array Radar (DAR) prototype system.
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Design
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01 May 2010
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by J. A. García, B. Bedia, R. Merlín, P. Cabral and J. C. Pedro
An experimental procedure is proposed for accurately characterizing the Vdd-to-AM and Vdd-to-PM nonlinearities in a Class E power amplifier (PA). Based on GaN HEMT technology,...
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Design
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01 Dec 2007
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by Marc Franco and Allen Katz
This paper investigates the use of silicon carbide (SiC) metal-semiconductor field effects transistors (MESFETs) in high-efficiency, class-E, RF power amplifiers in the VHF range. A maximum drain DC to RF efficiency of 87% was predicted and 86.8% achieved.
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Design
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05 Jun 2007
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by Neal Tuffy, Anding Zhu, and Thomas J. Brazil
This work outlines a design approach used for achieving highly efficient power amplification over a wide bandwidth, given narrowband passive harmonic load-pull results at a single center frequency.
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Design
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01 Jun 2011
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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 Raymond Pengelly, Scott Sheppard, Thomas Smith, Bill Pribble, Simon Wood and Carl Platis
Wide bandgap technology is now finding extended use in switching, control and low noise applications. Cree's GaN on silicon carbide (SiC) MMIC processes provide high drain to source breakdown voltage (typically 150 volts) resulting in robust transistor operation allowing, for example, simpler receiver protection circuitry.
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Design
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01 May 2011
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by David Yu-Ting Wu, Slim Boumaiza
Research on digital predistortion and advanced transmitters utilizing nonlinear PAs have begun to mitigate the concerns about nonlinearity.
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Article
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01 Feb 2010
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by Danish Kalim and Renato Negra
This paper presents a concept to design a compact planar multiharmonic load transformation network (MHLTN) for the realisation of highly efficient dual-band power amplifiers (PAs). The topology was applied to implement a class-E PA using a GaN High Electron Mobility Transistor (HEMT) in a hybrid design for GSM1810 and LTE2655 operation.
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Design
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01 Jun 2011
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Microwave office capabilities provide first-pass design success of complex 2.1-GHz circuits using GaN HEMTs.
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Articles
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01 Jun 2009
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by David Yu-Ting Wu, Farouk Mkadem, Slim Boumaiza
Abstract — A comprehensive approach for designing broadband and highly efficient power amplifier based on optimal impedance analysis and simplified real frequency technique SRFT) is presented.
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Design
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01 May 2010
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by Tian He; Uma Balaji
A Class F power amplifier (PA) at 2.5 GHz has been designed and fabricated. Test results show 15.7 dB gain with 75.75% power added efficiency (PAE ), at an input level of 25 dBm.
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Design
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01 Feb 2010
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by Simon M. Wood and Raymond S. Pengelly
This paper describes the use of a new large signal LDMOS FET model in the design of a high power, UMTS band 60W Doherty amplifier. This new model will be shown to be capable of providing accurate predictions of power, gain, efficiency and most importantly, linearity of the complete amplifier.
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Models
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15 Apr 2004
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by Bradley J. Millon, Simon M. Wood, Raymond S. Pengelly
2.5 and 5-watt average power (15 and 30-watt peak power) GaN HEMT amplifiers for WiMAX signal protocols have been designed and fabricated for use in the 5.5 to 5.8-GHz band.
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Design
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27 Oct 2008
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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 Dec 2011
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|
by P. Suebsombut, O. Koch, S. Chalermwisutkul
A class-AB power amplifier was designed for an envelope tracking (ET) application. Class-AB amplifier is widely
used in wireless communication systems due to the compromise between linearity and efficiency.
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Design
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01 May 2010
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|
by S. Lin and A. E. Fathy
A 50 to 550 MHz wideband gallium nitride (GaN) HEMT power amplifier with over 43 dBm output power and 63% drain
efficiency has been successfully developed.
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Design
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01 Jan 2011
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|
by D. E. Root, J. Xu, J. Horn, M. Iwamoto, and G. Simpson
It is demonstrated that Xparameters measured versus load at the fundamental frequency predict well the independent effects of harmonic load tuning on a 10W GaN packaged transistor without having to independently control harmonic loads during characterization.
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Design
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01 Apr 2010
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|
by Jingqi Wang, Yingjie Xu, and Xiaowei Zhu
In this paper, a digital predistorted inverse class-F GaN power amplifier with novel PAPR reduction technique, in
which not only peaks but also valleys of signal are clipped to reduce the PAPR as much as possible, is presented.
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Design
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01 Jun 2011
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by Gabriel Montoro, Pere Gilabert, Jordi Berenguer, and Eduard Bertran
This paper presents a new Digital Predistorter (DPD) to compensate for nonlinear distortion that arises in Envelope Tracking (ET) Power Amplifiers (PAs) driven by slew-rate limited versions of the real signal’s envelope.
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Design
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01 Jun 2011
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by Junghwan Moon, Junghwan Son, Jungjoon Kim, Ildu Kim, Seunghoon Jee, Young Yun Woo, and Bumman Kim
A Doherty amplifier assisted by a supply modulator is presented using 2.14 GHz GaN HEMT saturated power amplifier (PA). A novel envelope shaping method is applied for high power-added efficiency (PAE) over a broad output power range.
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Design
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01 May 2010
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by Junghwan Moon, Juyeon Lee, Junghwan Son, Jungjoon Kim, Seunghoon Jee, Seungchan Kim, and Bumman Kim
The effects of even-order nonlinear terms on ET transmitters are explored for the behavior model and digital predistortion technique.
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Design
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01 Oct 2011
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by Junghwan Moon, Jangheon Kim, Jungjoon Kim, Ildu Kim, Bummam Kim
This paper presents an approach to mitigating the knee voltage effect of the Doherty power amplifier (PA), especially on the carrier amplifier.
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Design
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01 Jan 2011
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by Bumman Kim, Ildu Kim, Junghwan Moon
A general overview and practical design methods for supply-modulated transmitters are presented. Disadvantages of the conventional EER transmitter are discussed, such as wideband sensitivity, power leakage, and poor PAE.
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Article
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01 Aug 2010
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by John W. Palmour
As wide bandgap devices begin to become commercially available, it is becoming clear that electrical efficiency improvement is one of the key drivers for their adoption.
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Design
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12 Nov 2006
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by Hossein Mashad Nemati, Alan L. Clarke, Steve C. Cripps, Johannes Benedikt, Paul J. Tasker, Christian Fager, Jan Grahn, and Herbert Zirath
In this paper, the efficiency of a GaN HEMT transistor and its intrinsic waveforms are measured at 0.9 GHz and investigated for load- and supply-modulation applications.
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Design
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01 May 2010
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by Pere Gilabert; Gabriel Montoro; Eduard Bertran; Jose A. Garcia
This paper presents an exhaustive description of a field programmable gate-array (FPGA) based set-up for envelope tracking and dynamic biasing of RF power amplifiers (PA). For testing purposes a GaN HEMT RF PA operating at 3.5 GHz was considered.
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Design
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01 Feb 2010
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by Jangheon Kim: Farouk Mkadem; Slim Boumaiza
This paper proposes a new broadband saturated power amplifier (SPA) with a distributed second harmonic termination supporting multi-band/multi-mode operation. Due to the multiple harmonic terminations, the proposed PA improves the frequency range where the PA can achieve a high efficiency.
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Design
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01 Sep 2010
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by Gil Wong Choi, Hyoung Jong Kim, Woong Jae Hwang, Suk Woo Shin, Jin Joo Choi, and Sung Jae Ha
This paper describes the design and fabrication of a highly efficient switching-mode Class-E Doherty power amplifier using gallium nitride (GaN) high electron mobility transistor (HEMT) for S-band radar applications.
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Design
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01 Jun 2009
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by S. Wood, P. Smith, W. Pribble, R. Pengelly, and J. Crescenzi
An article in High Frequency Electronics about the use of Cree's GaN HEMTs for WiMAX applications.
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Article
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01 May 2006
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by U. H. Andre, R. S. Pengelly, A. R. Prejs and S. M. Wood, and E. J. Crescenzi
An article in High Frequency Electronics about the recent advances in the use of Cree's GaN HEMTs for WiMAX applications.
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Article
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01 Jun 2007
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by Saptharishi Sriram, Helmut Hagleitner, Dan Namishia, Terry Alcorn, Thomas Smith, and Bill Pulz
We demonstrate for the first time improvement of radio-frequency (RF) gain of SiC MESFETs by using source-connected field plates (FPs).
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Design
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01 Sep 2009
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by Primit Parikh, Yifeng Wu, M. Moore, P. Chavarkar, U. Mishra, R. Neidhard, L. Kehias, T. Jenkins
AlGaN-GaN HEMTs have not only been identified as the technology of choice for next generation high-power, high frequency applications but recently have also garnered interest for low noise receiver applications.
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Article
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01 Aug 2002
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by S. T. Sheppard, R. P. Smith, W. L. Pribble, Z. Ring, T. Smith, S. T. Allen, J. Milligan and J. W. Palmour
An overview of hybrid and monolithic high-power microwave amplifiers using SiC MESFET and GaN HEMT active devices is presented. High power densities of 5.2 W/mm and 63% power added efficiency (PAE) have been demonstrated for SiC MESFETs at 3.5 GHz. This performance has driven the development of wide-bandwidth MMIC amplifiers, which have yielded 37 W of pulsed power at 3.5 GHz.
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Design
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24 May 2002
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by Kelvin Yuk, G.R. Branner and Claudia Wong
A method of determining the optimal harmonic terminations using accurate nonlinear computer models and load- and source-pull simulations is described.
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Design
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01 May 2010
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by Zachary D. Schwartz and George E. Ponchak
A hybrid, UHF-Band differential oscillator based on 10 W SiC RF Power Metal Semiconductor Field Effect Transistor (MESFET) has been designed, fabricated and characterized through 475 °C. The circuit is fabricated on an alumina substrate with thin film spiral inductors, chip capacitors, chip resistors, and wire bonds for all crossovers and interconnects.
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Design
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11 May 2005
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by Peter Wright, Aamir Sheikh, Chris Roff, P. J. Tasker and J. Benedikt
Interactive Forum paper from the 2008 International Microwave Symposium (IMS)
Presentation Supplement
This paper investigates the development of an inverse class-F design procedure for obtaining very high efficiency performance at high power levels. RF waveform engineering was used to obtain high efficiency inverse class-F waveforms at the device current-generator plane.
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Design
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15 Jun 2008
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by Yifeng Wu and Primit Parikh
The vacuum tubes used in today's millimeter-wave transmitters face an increasing threat from GaN HEMTs. Cree's Yifang Wu and Primit Parikh are leading the GaN charge with designs that incorporate field plates, iron-doped buffer layers and a thin AIN interlayer to deliver a record power at 30 GHz.
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Article
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01 Jan 2006
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by Simon Wood, Ray Pengelly, Don Farrell, and Carl Platis, Cree, Inc., and Jim Crescenzi, Central Coast Microwave Design
New GaN HEMT devices allow the design of high power amplifiers with the desired linearity and efficiency for 4G applications such as WiMAX, UMTS and WCDMA.
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Article
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01 May 2009
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by Troels S. Nielsen, Ulrik R. Madsen, Michael Dieudonné
A complete power amplifier design using new Nonlinear Vector Network Analyzer (NVNA) and X-parameter technologies. A high-power, pulsed Continuous Wave (CW) NVNA setup is presented and harmonic tuning capabilities of the measured X-parameter model is demonstrated using the same setup.
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Design
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01 Nov 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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by Moon, Seunghoon Jee, Jungjoon Kim, Junghwan Son, Seungchan Kim, Juyeon Lee, Seokhyeon Kim, and Bumman Kim
The practical operating conditions of class-F-1 amplifier are investigated by analyzing the current and voltage waveform shapings. In the experiment, the saturated amplifier is designed and implemented using Cree GaN HEMT CGH40010 at 2.655 GHz. It provides a power-added efficiency of 73.9% at saturated output power of 41 dBm.
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Design
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01 Oct 2011
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by Junghwan Moon; Jungjoon Kim; Bumman Kim
This paper presents the operation principle of Class-J power amplifiers (PAs) with linear and nonlinear output capacitors (Cout s). The efficiency of a Class-J amplifier is enhanced by the nonlinear capacitance because of the harmonic generation from the nonlinear Cout , especially the second-harmonic voltage component.
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Design
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04 Nov 2010
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by M. Akmal, V. Carrubba, J. Lees, S. Bensmida, J. Benedikt, K. Morris, M. Beach, J. McGeehan, P. J. Tasker
This paper demonstrates how the linearity performance of a 10W GaN HEMT can be dramatically improved by actively engineering the baseband impedance environment around the device.
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Design
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01 Jun 2011
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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 Peter Wright, Jonathan Lees, Johannes Benedikt, Paul J. Tasker, and Steve C. Cripps
The design and implementation of a class-J mode RF power amplifier is described. The experimental results indicate the class-J mode’s potential in achieving high efficiency across extensive bandwidth, while maintaining predistortable levels of linearity.
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Article
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01 Dec 2009
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A 10W GaN device from Cree achieving record efficiencies in excess of 81% was also demonstrated at IMS using an active harmonic load-pull capability from Mesuro, a new measurement company with ties to Cardiff University and Tektronix.
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Article
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01 Jul 2009
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by R. Marante, J. A. García, L. Cabria, T. Aballo, P. M. Cabral, and J. C. Pedro
Two vector nonlinear characterization procedures are presented, aimed at improving available GaN HEMT models for an accurate reproduction of the device behavior operating as a current source and in switched-mode RF PAs.
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Design
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01 May 2010
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by Abdullah AlMuhaisen, Peter Wright, J. Lees, P. J. Tasker, Steve C. Cripps and J. Benedikt
This paper introduces a novel approach for the realization of wide band (>octave) high-efficiency (>95%) high Power Amplifiers (PAs).
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Design
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01 May 2010
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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 S. Bensmida, K. Morris, J. Lees, P. Wright, J. Benedikt, P. J. Tasker, M. Beach, J. McGeehan
A new and simple Power Amplifier (PA) linearization method is proposed and demonstrated using a very high efficiency yet inherently nonlinear inverse class-F PA.
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Design
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01 Sep 2009
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by F. Fornetti, K.A. Morris, M.A. Beach
The present study investigates the behaviour and performance of commercially available GaN HEMTs provided by Cree Inc.
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Design
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01 Oct 2009
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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 Dr. Mike Cooke
Silicon Carbide (SiC) has been proposed for some time as a substrate for high-speed, high-temperature devices, and products are now entering the market. Dr. Mike Cooke reviews some of SiC's device opportunities and tough process challenges.
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01 Dec 2005
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by Gabriel Montoro, Pere L. Gilabert, Pedro Vizarreta and Eduard Bertran
This paper presents a practical application of a method for generating slew-rate limited envelopes in order
to drive the dynamic supply of envelope tracking (ET) power amplifiers (PAs).
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Design
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01 Jan 2011
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by Seunghoon Jee; Junghwan Moon; Jungjoon Kim; Junghwan Son; Bumman Kim
The switching behavior of Class-E power amplifiers (PAs) is described. Although the zero voltage switching can be performed properly, the charging process at the switch-off transition cannot be abrupt and the waveform deviates from the ideal shape, degrading the efficiency. For the operation above maximum frequency, the charging process should be even faster but it cannot follow. Moreover, the discharging process is not sufficiently fast and further degrades the efficiency. The discharging process is assisted by the bifurcated current at saturation. The performance of the Class-E PA above the maximum frequency is enhanced by the nonlinear , which helps to shape the voltage waveform. The bifurcated current itself cannot generate enough of a second-harmonic voltage component to shape the required voltage waveform. The performance of the Class-E PA can be further improved by a second-harmonic tuning and a conjugate matched output load, leading to the saturated PA. Compared with the Class-E PA, the saturated amplifier delivers higher output power and efficiency. A highly efficient saturated amplifier is designed using a Cree GaN HEMT CGH40010 device at 3.5 GHz. It provides a drain efficiency of 75.8% at a saturated power of 40.2 dBm (10.5 W).
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Design
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01 Jan 2012
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by R. Marante, L. Cabria, P. Cabral, J. C. Pedro, and J. A. García
In this paper, the impact of self heating on the linearity of a drain modulated GaN HEMT power amplifier (PA) is studied.
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Design
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01 Apr 2010
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by M. Akmal, J. Lees, S. Bensmida, S. Woodington, V. Carrubba, S. Cripps, J. Benedikt, K. Morris, M. Beach, McGeehan and P. J. Tasker
This paper demonstrates the significant effect of baseband impedance termination on the linearity performance of
a 10W GaN HEMT device driven to deliver a peak envelope power of approximately 40dBm.
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Design
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01 Sep 2010
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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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by Ahmed Sayed and Georg Boeck
This paper describes a two-stage 5-W broad-band amplifier covering the frequency range from 10 MHz to 2.4 GHz. The design procedure is given in detail, and the results are being discussed and compared with simulations.
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Design
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01 Jul 2005
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