HEMTs for wireless applications

Three new gallium nitride (GaN) high electron-mobility transistors (HEMTs) provide good linear power and efficiency for WiMAX and broadband wireless applications operating between 2.3 and 3.9GHz.

Cree is shipping sample quantities of three new gallium nitride (GaN) high electron-mobility transistors (HEMT).

Optimised for high efficiency, high gain and wide bandwidth, these linear power transistors provide exceptional linear power and efficiency for WiMAX and broadband wireless access applications operating between 2.3 and 3.9GHz.

The CGH27015S, contained in a small 3 x 3mm plastic over-mould QFN package, typically produces 2.5W of average output power and 28% drain efficiency over the frequency range of 2.3 to 2.9GHz.

This represents up to a 40% improvement in device efficiency when compared with traditional technologies such as silicon LDMOS or GaAs under WiMAX signals and requirements (802.16-2004).

It also has 15dB of small-signal gain and 2.0% error vector magnitude (EVM) under orthogonal frequency- division multiplexing (OFDM) modulation when operated at 28V.

The CGH35015S, also provided in an over-mould QFN package, typically produces more than 2.5W of average power and 28% drain efficiency with typical small-signal gain of 13dB over the frequency range of 3.3 to 3.9GHz.

This represents up to a 50% improvement in device efficiency when compared with silicon LDMOS or GaAs under WiMAX signals.

In addition, the CGH35030F transistor provides 4W of average power with 23% efficiency over the 3.3 to 3.9GHz frequency range.

This component has more than 11dB gain and 2% error vector magnitude (EVM) under OFDM modulation.

When employed in an efficiency-enhancement circuit, a pair of these transistors produced more than 10W of average power with over 42% efficiency in the 3.5GHz WiMAX band.

All three of the new Cree devices are EU RoHS-compliant.

"The CGH27015S and CGH35015S plastic over-mould GaN transistors allow our customers to employ low-cost, high-speed assembly methods while preserving outstanding RF performance with a RoHS-compliant device", says Jim Milligan, Cree Business Area Manager for RF products.

"The CGH35030F provides further flexibility for RF designers needing additional power at high efficiency to enable new system architectures such as distributed wireless base stations employing remote radio heads".

Back to top