Harmonically tuned GaN-HEMT Doherty power amplifier for 6 GHz applications
Harmonically tuned GaN-HEMT Doherty power amplifier for 6 GHz applications
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适用于 6 GHz 应用的谐波调谐 GaN-HEMT Doherty 功率放大器
DOI：
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发表时间：
2011
期刊：
影响因子：
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通讯作者：
Georg Boeck
中科院分区：
文献类型：
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作者：
D. Gruner;K. Bathich;A. A. Tanany;Georg Boeck
本文介绍了一种适用于6 GHz车载应用的GaN-HEMT Doherty放大器。为了提高整体的大信号性能，对所选裸芯片晶体管的谐波调谐进行了研究和实现。Doherty放大器在器件参考平面水平上进行了研究和优化，主要AB类和峰值C类放大器使用两个相同尺寸的8瓦GaN器件。测得的最大输出功率为41.5 dBm，峰值漏极效率为63%（功率附加效率为50%）。在6dB输出功率回退时，获得49%的漏极效率（42%功率附加效率）。通过根据IEEE 802.11p标准施加调制信号来测试放大器的线性度。在平均输出功率为34 dBm时，该高动态范围OFDM信号的漏极效率达到43%。经过数字预失真后，相关的邻道功率比可以从−31 dBc降至−43 dBc以下，而不会对效率性能产生显著影响。
In this paper a GaN-HEMT Doherty amplifier targeted for vehicular applications at 6 GHz is presented. The harmonic tuning of the selected bare-die transistors was investigated and implemented in order to improve the overall large-signal performance. The Doherty amplifier was studied and optimized on device reference plane level using two equally sized 8-Watt GaN devices for the main class-AB and the peaking class-C amplifiers. The measured maximum output power was 41.5 dBm with 63 % peak drain efficiency (50 % power added efficiency). At 6 dB output power back-off a drain efficiency of 49 % (42 % power added efficiency) was obtained. The linearity of the amplifier was tested by applying modulated signals according to the IEEE 802.11p standard. At 34 dBm average output power a drain efficiency of 43 % was achieved for this high dynamic range OFDM signal. After digital pre-distortion, the related adjacent channel power ratio could be reduced from −31 dBc to values below −43 dBc without significant impact on the efficiency performance.