As high-data-rate applications put more strain on LTE wireless networks, solutions such as small-cell base-stations (BTS) and carrier aggregation will be needed to bridge the bandwidth gap in high traffic areas. In response to broader bandwidth demand, Cree Inc of Durham, NC, USA has introduced a family of RF gallium nitride (GaN) high-electron-mobility transistors (HEMTs) that delivers bandwidth and efficiency performance to support busy LTE networks. Fabricated in plastic dual-flat no-leads (DFN) surface-mount packages, the new GaN HEMT RF transistors also provide the affordability needed to replace less efficient silicon or gallium arsenide (GaAs) transistors in these applications, says Cree.
“The trend of ever-increasing amounts of data-rich applications will drive the need for small-cell deployment to improve wireless network performance,” says Tom Dekker, director of sales & marketing of Cree’s RF business unit. “Our industry-leading GaN technology will provide the desired bandwidth, flexibility, efficiency and affordability our small-cell customers demand,” he adds.
The new GaN HEMT DFN product family includes 28V and 50V, 15W and 30W unmatched transistors. The frequency-agile transistors are capable of operating at 700MHz-3.8GHz instantaneous, and may be optimized for band splits. Multi-band capability creates design flexibility that helps small cell OEMs speed their time to market and allows operators to reconfigure the same small-cell unit for different market requirements.
In high-efficiency applications, Cree’s GaN HEMT RF transistors help to reduce the size and weight of LTE cellular network transmitters and simplify thermal management. These efficiency gains generate significant energy savings in operational costs. Cree developed Doherty reference design CDPA27045 utilizing 15W and 30W HEMT DFN transistors to demonstrate the technology’s efficiency. The design delivers about 50% drain efficiency at 10W average power under a LTE 7.5dB peak-to-average ratio signal, and covers 2.5-2.7GHz instantaneous RF bandwidth while offering 16dB of linear gain.
The new family of GaN HEMT DFN RF transistors is based on Cree’s qualified 50V, 0.4μm-gate-length process. Samples and reference designs are available for the CGH27030S (30W, 28V, 0.4μm), CGHV27015S (15W, 50V, 0.4μm) and CGHV27030S (30W, 50V, 0.4μm) GaN HEMT transistors.
