CG2H40025

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 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.

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.

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.

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.

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 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.

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.

by David Sardin – Zoya Popovic – This work discusses the design of a GaN power amplifier demonstrating high efficiency over more than a decade bandwidth using coaxial baluns and transformer matching networks to achieve over a 50 MHz – 500 MHz bandwidth. The power amplifier demonstrates a power added efficiency of 83% – 64% over a full bandwidth with 15 dB compressed gain at peak PAE.

by Kenle Chen and Dimitrios Peroulis – This paper presents a novel adaptive power amplifier (PA) architecture for performing dynamic-load-modulation. For the first time – a dynamically-load-modulated PA design that achieves octave bandwidth – high power and high efficiency simultaneously is experimentally demonstrated. This PA design is based on a commercial GaN HEMT.

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.

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.

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.

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.

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.

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.