NEC nitride power transistor delivers 2.3W output

NEC Corp. has developed a nitride semiconductor power transistor capable of 2.3W power amplification in the sub-millimeter band (30GHz) - almost thrice the output power of previous chip - and is expected to substantially contribute to the development of wireless communications.

The transistor provides watt-grade power amplification without the need for the power divider/combiner that conventionally generated larger chip sizes and increased power loss. This results to a size 80 percent smaller than previous devices but can still cover the 22GHz, 26GHz, and 38GHz HF bands.

The device employs 0.25?m ultra-fine gate electrodes using an electron beam lithography and heterojunctions of GaN and AlGaN to realize a power gain cutoff frequency of 120GHz, drain current density of up to 1A per 1mm-wide gate. It also adopts a silicon carbide substrate to allow parallel transistor elements to be operated at the same channel temperature.

NEC achieved a maximum output power of 2.3W (continuous wave operation) at an input frequency of 30GHz when a 30V bias voltage is applied to chip with a total gate width of 0.36mm.