The effect of baseband impedance termination on the linearity of GaN HEMTs
The effect of baseband impedance termination on the linearity of GaN HEMTs
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基带阻抗终端对 GaN HEMT 线性度的影响
DOI：
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发表时间：
2010
期刊：
影响因子：
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通讯作者：
P. Tasker
中科院分区：
文献类型：
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作者：
Muhammad Akmal;J. Lees;S. Bensmida;S. Woodington;V. Carrubba;S. Cripps;J. Benedikt;K. Morris;M. Beach;J. Mcgeehan;P. Tasker
本文演示了基带阻抗终端对10 W GaN HEMT器件线性度性能的显著影响，该器件被驱动以提供约40 dBm的峰值包络功率。本文还提出了一种先进的有源中频负载牵引测量系统的进一步改进，以允许精确的独立控制所有重要的基带组件产生的结果，使用的多音激励。与经典理想短路情况相比，特定基带阻抗的出现使IM3和IM5互调产物分别提高了20 dBc和17 dBc。正如对该器件的预期，这是通过模拟位于史密斯圆图之外的适当负阻抗来实现的，并且当将该观察结果与包络跟踪PA架构一起考虑时，这提出了使用用于提高PA效率的机制显著提高PA线性度的有趣可能性。
This paper demonstrates the significant effect of baseband impedance termination on the linearity performance of a 10W GaN HEMT device driven to deliver a peak envelope power of approximately 40dBm. The paper also proposes a further refinement to a state-of-art active IF load-pull measurement system to allow the precise independent control of all significant baseband components generated as a result of the multi-tone excitation used. The presentation of specific baseband impedances has delivered a 20dBc and 17dBc improvement in IM3 and IM5 inter-modulation products respectively, relative to the case of a classical, ideal short circuit. As expected for this device, this was achieved by emulating appropriate negative impedances lying outside of the Smith chart, and when this observation is considered alongside the Envelope Tracking PA architecture, this raises the interesting possibility of significantly improving PA linearity using the very mechanisms that are employed to improve PA efficiency.