CG2H40010F, CGH27015F, CGH27030F, CGH35015F, CGH35030F, CGH40010F, CGH40025F, CGH55015F1, CGH55015F2, CGH55030F1, CGH55030F2, CGHV40030F

CG2H40010F, CG2H40025F, CGH27015F, CGH27030F, CGH35015F, CGH35030F, CGH40010F, CGH40025F, CGH55015F1, CGH55015F2, CGH55030F1, CGH55030F2, CGHV40030F

CG2H40010P, CG2H40025P, CGH27015P, CGH27030P, CGH35015P, CGH40010P, CGH40025P, CGH55015P1, CGH55015P2, CGH55030P1, CGH55030P2, CGHV40030P

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.

by Jorge Moreno Rubio; Jie Fang; Vittorio Camarchia; Roberto Quaglia; Marco Pirola; Giovanni GhioneWe discuss the design, realization and experimental characterization of a GaN-based hybrid Doherty power amplifier for wideband operation in the 3–3.6-GHz frequency range. The design adopts a novel, simple approach based on wideband compensator networks. Second-harmonic tuning is exploited for the main amplifier at the upper limit of the frequency band, thus improving gain equalization over the amplifier bandwidth.

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.

by Raymond S. Pengelly, William Pribble, Thomas Smith

This Simulation of power amplifiers (PAs) for modern wireless base station and small cell systems is an essential part of the design process. At a cell site, the PA consumes the bulk of the dc power, generates the most heat, and thus represents the greatest operational cost. Maximum PA efficiency is a necessity to manage these costs, which is a sizeable challenge in a PA that also must be highly linear to support the complex multilevel modulation types and wide bandwidths used for current and developing wireless transmission standards. Accurate simulation allows the PA designer to meet these challenges by exploring the available design options and then optimizing the circuit that is selected for the application.

by Deniz Gezmiş Tas; Osman Ceylan; H. Bülent Yağcı - In this article, an RF power amplifier which has a crucial importance for RF transceivers is designed and implemented. The main aim of the design is making the power amplifier linear at the center frequency 1.8 GHz. Linearity was measured with two tone test and according to the result of the test, the Carrier-to-Intermodulation (C/I) ratio should have been above 30 dB and two fundamental carriers with the 5 MHz space should be at least 1.25 Watt. Also, efficiency was tried to be kept as high as possible.

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.

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.

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.

by Bumjin Kim, D. Derickson, and C. Sun - A class B and a class F power amplifier are described using a GaN HEMT device.

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.

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.

by Moon, Junghwan Son, Juyeon Lee, Jungjoon Kim, Seunghoon Jee, Seungchan Kim, and Bumman KimA 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.

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.

by Raymond S. Pengelly, Simon M. Wood, James W. Milligan, Scott T. Sheppard, and William L. Pribble

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).

by Neal Tuffy; Lei Guan; Anding Zhu; Thomas J Brazil - This paper describes the design approach employed for achieving approximated continuous Class-F power amplifier (PA) modes over wide bandwidths. The importance of the nonlinear device capacitance for wave-shaping the continuous Class-F voltage and current waveforms is highlighted, thus reducing the device sensitivity to second and third harmonic impedance terminations.

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.

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.

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 DesignThis presentation discusses attributes of GaN HEMTs, Cree GaN HEMT models, design examples (Broadband CW Amplifiers and Linear WiMAX Amplifier), and future model improvements.

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.

by Junghwan Moon; Seunghoon Jee; Jungjoon Kim; Jangheon Kim; Bumman Kim - Operational behaviors of the class-F and class-F amplifiers are investigated. For the half-sinusoidal voltage waveform of the class-F amplifier, the amplifier should be operated in the highly saturated region, in which the phase relation between the fundamental and second harmonic currents are out-of-phase. The class-F amplifier can operate at the less saturated region to form a half sinewave current waveform. Therefore, the class-F amplifier has a bifurcated current waveform from the hard saturated operation, but the class-F amplifier operates as a switch at the saturated region for a second harmonic tuned half-sine waveform.

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,...

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.

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.

by Zhebin Wang and Chan-Wang Park - This paper presents a novel method by using resonators in both input and output matching networks to design a tri-band GaN HEMT power amplifier. Two parallel resonators in series as one frequency selection element are used for each operation frequency. By applying this frequency selection element in both input and output matching networks constructed with microstrip line, tri-band matching network is realized. With our proposed frequency selection element, we can use the conventional L-type structure to design matching network for three frequencies so that the design analysis procedure is easier. We also propose a new simplified output matching network by using bias line to match the output impedance to reduce the number of resonators. To demonstrate our method, we fabricate a tri-band power amplifier that can work at 1 GHz, 1.5 GHz, and 2.5 GHz concurrently. Experimental results show that the output power is 39.8 dBm, 40.8 dBm, and 39.2 dBm with 56.4%, 58.3%, and 43.4% power added efficiency (PAE) at 1 GHz, 1.5 GHz and 2.5 GHz, respectively.

by Thomas M. Hone; Souheil Bensmida; Kevin A. Morris; Mark A. Beach; Joe P. McGeehan; Jonathan Lees; Johannes Benedikt; Paul J. Tasker - Mathematical analysis of Doherty amplifiers have assumed many simplifications. Most notably, the peaking amplifier does not contribute power into the load and the peaking stage has an observed impedance of infinity. This paper will show that these simplifications impair the performance of a single-input Doherty amplifier and that phase tuning for compensation is needed to improve the overall system performance.

by Karun Rawat; Fadhel M. GhannouchiThis paper proposes a design methodology for dual-band Doherty power amplifier (DPA) with performance enhancement using dual-band phase offset lines. In the proposed architecture, 50-Ωdual-band offset lines with arbitrary electric lengths at two frequencies are key components, and a novel analytical design solution has been proposed for their design and implementation.

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.

by Anh Nghiem Xuan and Renato Negra - A new technique for designing concurrent multiband biasing networks for multiband RF power amplifiers is presented. The proposed design technique can theoretically be applied for a large number of frequency bands. The biasing network (BN) is composed of a transmission line and high impedance quaterwave open stubs (QWOS) that are located at appropriate positions along the transmission line. Two tri-band BNs for 1.49 GHz, 2.15 GHz and 2.65 GHz frequencies were designed, fabricated and display very good performance with regard to the input impedance seen looking toward the BNs from the active devices, such as FETs, are approximately open for all three bands.

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.

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.

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.

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.

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.

by Karun Rawat; Mohammad S. Hashmi; Fadhel M. Ghannouchi - The emergence of increasing multifunctionality and high data rate advanced wireless standards, such as WiMAX and LTE-advanced, requires communication systems capable of operating at multiple frequencies simultaneously. This situation has led to scenarios where the radios with the ability to function at several distinct frequencies are required. Seamless transition from one existing standard (e.g., 3G) to upcoming standards (e.g., 4G) with backward compatibility is also a motivating factor for the deployment of multiband radio architectures.

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.

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.

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.

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.

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.

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.

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.

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.

by Ildu Kim, Jangheon Kim, Junghwan Moon, Jungjoon Kim, and Bumman KimDemonstrating 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.

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.

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.

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.

by Raymond Quéré; Raphael Sommet; Philippe Bouysse; Tibault Reveyrand; Denis Barataud; Jean Pierre Teyssier; Jean Michel Nébus - In this paper Low Frequency (LF) parasitic effects are assessed through three kinds of measurements. It is shown that LF S-parameters measurements allow to extract the thermal impedance of Heterojunction Bipolar Transistors (HBTs) and to put dispersive effects of AlGaN/GaN High Electron Mobility Transistors (HEMTs) into evidence. Large signal (RF pulsed and two tone intermodulation) confirm the impact of those parasitic effects on performances of Power Amplifiers.

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.

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.

by Wilfried Demenitroux, Christophe Mazière, Emmanuel Gatard, Stéphane Dellier, Michel Campovecchio and Raymond Quéré - This paper presents a complete validation of the new behavioral model called the multiharmonic Volterra (MHV) model for designing wideband and highly efficient power amplifiers with packaged transistors in computer-aided design (CAD) software. The MHV models of 10- and 100-W packaged GaN transistors have been extracted from time-domain load–pull measurements under continuous wave and pulsed modes, respectively.

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.

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.

by Donald A. Gajewski, Scott Sheppard, Simon Wood, Jeff B. Barner, Jim Milligan, and John Palmour.

This paper discusses the reliability performance of Wolfspeed GaN/AlGaN high electron mobility transistor (HEMT) MMIC released process technologies, fabricated on 100 mm high purity semi-insulating (HPSI) 4H-SiC substrates.

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.

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).

by Francesco Fornetti, Mark Beach; James G. Rathmell - GalliumNitride (GaN) solid-state devices are emerging as a replacement for vacuum electron devices (VED) in radar systems. These solid-state devices have significant thermal and trapping effects that, although not ruling out their use, do complicate it. This paper evaluates several commercial GaN devices, using pulse testing, under conditions typical of modern, high-frequency radar systems.

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.

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.

by Jialin Cai; Thomas J. Brazil - As a kind of superset of S-parameters, X-parameters are becoming increasingly popular in non-linear device simulation and measurement. Due to their good accuracy and convenient extraction procedures, X-parameter-based transistor device models have so far been mainly used in power amplifiers design. They have been limited to this kind of design up to now because the X-parameter models extracted are only suitable for fundamental frequency circuit design.