X波段GaN千瓦级功率放大器的设计

Study of X-band GaN Power Amplifier with Power Higher than Kilowatt

为满足新型雷达对千瓦级大功率放大器的需求,采用0.25μm GaN HEMT工艺研制了一款输出功率大于2000 W的X波段内匹配功率放大器。通过背势垒层结构与双场板结构提高器件击穿电压,使GaN HEMT管芯的工作电压达到60 V。通过负载牵引得到管芯最优阻抗,采用T型匹配网络和功率分配/合成器将管芯阻抗匹配到50Ω。在工作电压60 V、占空比1‰、脉宽5μs测试条件下,9.0~9.4 GHz频段内输出功率大于2000 W,最大功率密度达到10.4 W/mm,功率增益大于7 dB,功率附加效率大于37.2%。

Based on the demand for the amplifier with power higher than kilowatt in new type radar,an X-band GaN internally matched power amplifier with output power higher than 2000 W was presented,which was fabricated by 0.25μm GaN HEMT technology.The GaN HEMT chip operating at 60 V voltage was developed,whose breakdown voltage improved by using back-barrier layer structure and dual field-plate structure.The optimal matching impedance of the chip was found by loadpull simulation.With the combination of T-shaped matched network and power divider/combiner,the matching impedance of the chip was transformed to standard 50Ω.Under the operating voltage of 60 V and the pulse condition(1‰duty cycle and 5μs pulse width),the output power is higher than 2000 W,the maximum power density is 10.4 W/mm,the power gain is more than 7 dB,the power added efficiency is higher than 37.2%from 9.0 GHz to 9.4 GHz.