Title :
High Efficiency Digital GaN MMIC Power Amplifiers for Future Switch-Mode Based Mobile Communication Systems
Author :
Maroldt, Stepehn ; Haupt, C. ; Kiefer, R. ; Bronner, W. ; Mueller, S. ; Benz, W. ; Quay, R. ; Ambacher, O.
Author_Institution :
Fraunhofer Inst. for Appl. Solid State Phys. (IAF), Freiburg, Germany
Abstract :
A high efficiency digital MMIC amplifier for mobile communication switch-mode concepts was designed by utilizing a 0.25 mum GaN HEMT technology with ftau of 32 GHz. A comparative investigation of two different driver concepts for a 1.2 mm GaN HEMT PA is shown. The MMICs were on-wafer evaluated for class-D and class-S operation. A drain efficiency of 70% for an output power of 4.4 W for a band pass delta-sigma (BPDS) class-S input signal at a bit rate of 3.6 Gbps equivalent to a 0.9 GHz fundamental was obtained. For the first time the operating mode up to 8 Gbps (2 GHz) is shown with an efficiency of 62%, demonstrating the prospect of future use of GaN HEMTs for switch mode amplifier concepts.
Keywords :
HEMT integrated circuits; III-V semiconductors; MMIC power amplifiers; field effect digital integrated circuits; gallium compounds; integrated circuit design; mobile communication; wide band gap semiconductors; GaN; HEMT technology; band pass delta-sigma class-S input signal; bit rate; bit rate 3.6 Gbit/s; bit rate 8 Gbit/s; class-D operation; class-S operation; digital MMIC power amplifier; drain efficiency; efficiency 62 percent; efficiency 70 percent; frequency 0.9 GHz; frequency 2 GHz; frequency 32 GHz; high electron mobility transistor; monolithic microwave integrated circuit; output power; power 4.4 W; size 0.25 mum; size 1.2 mm; switch-mode based mobile communication systems; Bit rate; Communication switching; Driver circuits; Gallium nitride; HEMTs; High power amplifiers; MMICs; Mobile communication; Power generation; Switches;
Conference_Titel :
Compound Semiconductor Integrated Circuit Symposium, 2009. CISC 2009. Annual IEEE
Conference_Location :
Greensboro, NC
Print_ISBN :
978-1-4244-5191-3
Electronic_ISBN :
1550-8781
DOI :
10.1109/csics.2009.5315720
