CG2H40010

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

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 – Wolfspeed 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 Wolfspeed GaN HEMT.

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 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 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 Wolfspeed – GaN/AlGaN HEMT MMIC process technology – fabricated on 100 mm high purity semi-insulating (HPSI) 4H-SiC substrates.

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 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 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 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 Wolfspeed 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 F. Fornetti – K.A. Morris – M.A. Beach – The present study investigates the behaviour and performance of commercially available GaN HEMTs provided by Wolfspeed.

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 Wolfspeed GaN HEMT CGH40010 at 2.655 GHz. It provides a power-added efficiency of 73.9% at saturated output power of 41 dBm.

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 Wolfspeed – following a class AB and C scheme for the main and peak module – respectively.

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.