基于GaN HEMT 多倍频程高效率功率放大器设计

使用GaN HEMT 功率器件,设计了一款多倍频程高效率功率放大器。利用负载牵引技术分析输入功率、偏置电压、工作频率对功率器件输出阻抗的影响,从而寻找出满足宽带性能的最优阻抗区域;输入、输出匹配网络采用了切比雪夫多节阻抗变换器的综合设计方法,很好地拓展了匹配网络的带宽性能,从而实现了0. 8 ~4. 0 GHz(相对带宽133%)多倍频程高效率功率放大器电路。连续波大信号测试结果表明:在0. 8 ~ 4. 0 GHz 的频率范围内输出功率为39. 5 ~42. 9 dBm,漏极效率为54. 20% ~73. 73%,增益为9. 4 ~12. 0 dB。在中心频率2. 4 GHz 未利用线性化技术的情况下使用5 MHz WCDMA 调制信号测试得到邻近信道泄漏比(ACLR)为-27. 2 dBc。设计的工作频率能够覆盖目前主要的无线通信系统GSM900M、WCDMA、DCS1800 LTE、PCS1900 LTE、3. 5GHz WiMAX 以及下一代移动通信系统(5G)等。

Design of Multi-Octave High Efficiency Power Amplifier Based on GaN HEMT Device

This paper presents a multi octave broadband high efficiency power amplifier using GaN HEMT device. The optimal impedance regions of the active device was found by loadpull simulation. The Chebyshev multi-section matching transformers are employed to design input and output matching networks with extended bandwidth, thus achieving multi-octave broadband high efficiency power amplifier at the frequency band of 0. 8 ~4. 0 GHz (133% fractional bandwidth). High efficiency wideband power amplifier is designed and experimented, the measured results show a drain efficiency (DE) of 54. 20% ~73. 73% with an output power of 39. 5 ~42. 9 dBm and the gain of 9. 4 ~12 dB. For a 5 MHz WCDMA signal, the adjacent channel leakage ratio of the power amplifier reaches 27. 2 dBc without digital predistortion at center frequency 2. 4 GHz. The frequency range of this paper covers modern wireless communication systems like GSM900M, WCDMA, DCS1800 LTE, PCS1900 LTE, 3. 5 GHz WiMAX and 5G etc.