Cree Semiconductor Re-Enters High-Power RF Transistor Market

Cree Semiconductor Re-Enters High-Power RF Transistor Market SUMMARY HED: Gallium nitride transistors deliver 300 Watts at 2.7 GHz At the start of the DTV transition, Westinghouse and Cree partnered to show a high-power solid-state transmitter using silicon carbide transistors. I wrote about the Cree device in my RF Technology for November 1993. However, as far as I know, none of these transmitters were ever used for broadcasting.

Cree is back in the RF power amplifier business, this time targeting 2.7 GHz wireless bands with a new family of high power, low-cost Gallium Nitride (GaN) RF transistors based on an innovative package design.

The initial products include what Cree claimed is the industry's first 300 Watt plastic-packaged transistor operating at 2.7 GHz. It offers saturated power efficiency of 65 percent and provides broadband capability at a price that Cree claimed was nearly half that as compared to the same GaN transistors using standard ceramic packaging.

"Cree's newest family of high power plastic products will drive down the cost of GaN transistors to a point that is nearing Si LDMOS levels and will accelerate broader adoption in telecom applications," said Lance Wilson, research director at ABI Research. "This will make GaN transistors a principle choice for next-generation wireless networks."

The new Cree GaN HEMT RF transistors are available at power levels of 60, 100, 150, 200 and 300 Watts and they can operate at frequencies up to 3.8 GHz. Pre-matched transistors are available for cellular bands, including 690 to 960 MHz, 1800 to 2300 MHz and 2300 to 2700 MHz.

I doubt that Cree will get back in the broadcast market, but given the power capability, cost and frequency range of these devices it will be interesting to see if any TV transmitter manufacturers consider their new GaN devices.

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Doug Lung is one of America's foremost authorities on broadcast RF technology. He has been with NBC since 1985 and is currently vice president of broadcast technology for NBC/Telemundo stations.