Cree, Inc. has introduced two industry-leading GaN HEMT (high-electron-mobility transistor) devices that solve a number of long-standing issues for radar systems employing traditional travelling-wave-tube (TWT) amplifiers. GaN-based solid-state amplifiers operating at 50 V are not prone to the failure mechanisms seen with high-voltage (kV) TWT power supplies, thus providing longer lifetimes. Also, such solid-state systems provide near-instant-on capability – with no warm up, longer detection ranges and improved target discrimination.
Conceived from the start to enable these system benefits, Cree’s two new GaN RF transistors were engineered to provide the highest power and efficiency housed in a small package size. The first device, a 350-W/50-Ω, fully matched GaN HEMT is the highest-power C-Band transistor available on the market. The second, a 500-W/50-Ω GaN HEMT, is the highest power S-band transistor fully matched to 50 Ω in a single-ended package of its size.
“Cree’s new C- and S-band products break power records for GaN power and efficiency performance housed in a small 50-Ω package. This efficient power enables the economical combination of transistors to achieve multi-kilowatt power amplifiers required for defense, weather and air-traffic-control radar,” said Tom Dekker, director of sales and marketing, Cree RF. “If we consider the figure of merit for RF power output relative to the area of a 50-Ω package, Cree’s 350-W C-band device beats the closest commercial GaN competitor by an estimated 3.5 times. Using the same figure of merit, Cree’s 500-W S-band device raises the bar by 45 percent over other commercial S-band products.”
Offering pulsed saturated power performance typically greater than 400 watts, the CGHV59350 is most often used in ground-based defense and Doppler weather radar systems. The 50-Ω, fully matched GaN HEMT operates over a 5.2 to 5.9-GHz bandwidth, exhibits 60 percent typical drain efficiency, and is packaged in an industry-standard 0.7” × 0.9” ceramic/metal flange package.
Delivering 700 watts of typical saturated RF pulsed power, the CGHV31500F is offered for air-traffic-control-radar systems. The 50-Ω, fully matched GaN HEMT operates over a 2.7 to 3.1-GHz bandwidth, exhibits 12-dB power gain, and is packaged in an industry-standard 0.7” × 0.9” ceramic/metal flange package.
