CGH60008D

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 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 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.

by José A. García – Reinel Marante – María N. Ruiz – In this paper – the design and performance of class E2 resonant topologies for DC/DC power conversion at Ultra High Frequencies (UHF) are considered. Combining the use of RF GaN HEMT devices – both for the inverter and the synchronous rectifier – with high Q lumped-element terminating networks – peak efficiency values over 70% may be obtained. Control strategies based on carrier bursting – switching frequency modulation – or outphasing are also shown to be feasible. Taking advantage of their improved dynamic response – when compared to low frequency more traditional switched-mode converters – a class E3 polar transmitter for the EDGE standard has been designed and tested at 770 MHz – offering an average global efficiency over 46% at 4.3 W of output power – through RF-based amplitude and phase constituting branches.

by Rocco Giofrè; Paolo Colantonio; Franco Giannini; Luca Piazzon – In this letter – a new output combining network for the implementation of a Doherty Power Amplifier (DPA) is presented. The proposed topology simultaneously allows the active load modulation and the output matching – by adopting more realizable elements than the standard DPA – especially when high output power levels are required. The innovative design approach is demonstrated through a practical prototype realization based on GaN-HEMT devices. Experimental results have shown a 65%–48% efficiency at about 42–36 dBm output power with a gain compression lower than 1.5 dB from 1.95 to 2.25 GHz.

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.