S-band RF power transistor for air traffic control radar applications

November 14, 2012 // By Jean-Pierre Joosting
Microsemi Corporation has expanded its family of RF transistors based on gallium nitride (GaN) on silicon carbide (SiC) technologies with an S-band 500 W RF device. The 2729GN-500 is targeted at high-power air traffic control airport surveillance radar (ASR) applications. ASR is used to monitor and control aircrafts in the terminal within approximately 100 miles of an airport.

The 2729GN-500 transistor delivers unparalleled performance of 500 W of peak power with 12 dB of power gain and 53 percent drain efficiency over the band 2.7 to 2.9 GHz to provide the maximum power in a single device covering this band. Key product features include: a standard pulse burst format of 100 µs, 10 percent DF (microseconds); over 11.5 dB minimum power gain; drain bias, Vdd, of +65 V; and a low thermal resistance of 0.2 °C/W

GaN on SiC high electron mobility transistor (HEMT) benefits include a single-ended design with simplified impedance matching, replacing lower power devices that require additional levels of combining; a rugged performance that improves system yields; and high peak power and power gain for reduced system power stages and final stage combining.

A single stage pair provides 1.0 kW peak output power with margin, four-way combined to provide full system 2 kW peak output power. High operating voltage at 65 V reduces power supply size and DC current demand. Further, amplifier size is 50 percent smaller than devices built with silicon bipolar junction transistors (Si BJT) or laterally diffused metal oxide semiconductor (LDMOS) devices.

The 2729GN-500 is offered in a single-ended package and is built with 100 percent high-temperature gold (Au) metallization and wires in a hermetically solder-sealed package for long-term military reliability.