At the 2009 IEEE/MTT-S International Microwave Symposium in Boston, Cree demonstrated its the CGH40120F and CGH40180PP devices — the company's latest broadband GaN HEMT transistors — with Class A/B amplifiers. The demonstration amplifiers feature high efficiency and high power under continuous-wave operation, with typical power-added efficiencies (PAE) of 70% at saturated powers of 120 W (CGH40120F) and 180 W (CGH40180PP).
“A number of very-high-efficiency amplifier architectures, routinely used at lower frequencies for audio and UHF applications, are being realized at much higher RF and microwave frequencies using GaN transistors,” said Jim Milligan, Cree director for RF and microwave products. “Published research indicates greater than 80% PAE using Class D, E, F and J amplifier architectures with Cree GaN HEMT transistors at frequencies over 2 GHz.
“More typical Class A/B operation can also offer exceptional efficiency, validated by the demonstrations. Cree GaN transistors offer system designers a wide range of choices, supporting diverse application requirements.”
The CGH40120F and CGH40180F are the newest members of Cree's general-purpose transistor product family. Samples and fixtures are available through Digi-Key. Large-signal models for Agilent's ADS or AWR's MWO simulators are available directly from Cree.