Cree introduces GaN HEMTS for TWT Radar Systems
Cree has introduced two GaN HEMT devices designed to solve a number of long-standing issues for radar systems employing travelling wave tube (TWT) amplifiers.
According to the company, GaN-based amplifiers operating at 50V are not prone to the failure mechanisms seen with high voltage (kV) TWT power supplies, and so provide longer lifetimes. Also, being solid state systems, they provide near-instant on capability - with no warm up, longer detection ranges and improved target discrimination.
The first device, a 350W/50 fully matched GaN HEMT is claimed to be the highest power C-Band transistor available on the market. The second, a 500W/50 GaN HEMT, is a high power S-Band transistor fully matched to 50Ω in a single-ended package of its size. Both devices will be demonstrated at the International Microwave Symposium, from May 17 - 21 in Phoenix, Arizona.
"Cree's new C- and S-Band products break power records for GaN power and efficiency performance housed in a small 50 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 50Ω package, Cree's 350W C-Band device beats the closest commercial GaN competitor by an estimated 3.5 times. Using the same figure of merit, Cree's 500W S-Band device raises the bar by 45 percent over other commercial S-Band products."
Offering pulsed saturated power performance typically greater than 400W, the CGHV59350 is most often used in ground-based defense and Doppler weather radar systems. The 50Ω, fully matched GaN HEMT operates over a 5.2 to 5.9GHz bandwidth, exhibits 60 percent typical drain efficiency, and is packaged in an industry standard 0.7in x 0.9in ceramic/metal flange package.
Delivering 700W of typical saturated RF pulsed power, the CGHV31500F is offered for air traffic control radar systems. The 50, fully matched GaN HEMT operates over a 2.7 to 3.1GHz bandwidth, exhibits 12dB power gain, and is packaged in an industry standard 0.7in x 0.9in ceramic/metal flange package.
