Class-X—Harmonically Tuned Power Amplifiers With Maximally Flat Waveforms Suitable for Over One-Octave Bandwidth Designs
Class-X—Harmonically Tuned Power Amplifiers With Maximally Flat Waveforms Suitable for Over One-Octave Bandwidth Designs
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DOI：
10.1109/tmtt.2018.2791971
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发表时间：
2018-01
影响因子：
4.3
通讯作者：
Xiang Li;M. Helaoui;Xuekun Du
中科院分区：
文献类型：
--
作者：
Xiang Li;M. Helaoui;Xuekun Du
本文提出了一种具有最大平坦波形的调谐功率放大器的新理论--X类功率放大器。这种类型已经被开发来实现最大平坦的波形。在这一类中，建立了基波负载阻抗和独立设置的二次和三次谐波负载阻抗之间的关系，以保持恒定的输出功率和恒定的效率。当二次和三次谐波阻抗同时变化且彼此独立时，这种关系确定了最优基波负载设计空间。通过独立地改变二次和三次谐波阻抗，在宽带功率放大器的设计中获得了更大的灵活性。用Cree公司的10W氮化镓(GaN)器件进行了实验设计，验证了X类功率放大器的理论及其宽带特性。该设计的漏极效率大于70%，输出功率在一个倍频程以上的带宽内变化在3分贝以内。
This paper proposes a new theory for harmonically tuned power amplifiers (PAs) with maximally flat waveforms, Class-X PAs. This class has been developed to achieve maximally flat waveforms. In this class, the relationship between the fundamental load impedance and the independently set second- and third-harmonic load impedances is established to maintain constant output power with constant efficiency. This relationship sets an optimum fundamental load design space when the second- and third-harmonic impedances are varied simultaneously and independently of each other. By varying the second- and third-harmonic impedances independently, higher flexibility in the design of broadband PAs is obtained. The theory of Class-X PA and its broadband characteristics were validated with an experimental design example using a Cree’s 10-W Gallium Nitride (GaN) device. This design showed a measured drain efficiency higher than 70% and output power within 3-dB variation over more than one-octave bandwidth.