准连续逆F类功率放大器的紧凑型设计

Compact design of quasi-continuous inverse Class-F power amplifier

摘要:

为满足现代无线通信系统对射频功率放大器（PA）在高功率、宽带高效率,以及小型化方面的需求,提出了一种在P/L/S波段（特别是L波段）适用于高功率输出的宽带高效率PA的设计方法。首先,基于连续逆F类PA高效率阻抗匹配区域的拓展原理及基波低通匹配电路的阻抗特性,提出了准连续逆F类PA的谐波阻抗高效率区域及对应的输出电路拓扑结构。其次,通过有效利用高功率PA大尺寸晶体管的寄生参数,并复用基波与谐波输出匹配电路元件,在宽频带内以较少的元件实现高效率匹配的紧凑型设计,显著降低了电路复杂度。最后,为验证提出的设计方法,采用氮化镓高电子迁移率晶体管（GaN HEMT）作为放大器的主要器件,设计了一款适应于1.3~1.9 GHz频段的准连续逆F类高功率宽带高效率PA,经实验测试,其饱和输出功率达到46.01~46.73 dBm,功率增益在24.01~24.73 dB之间,同时实现了功率附加效率（PAE）65.1%~69.6%,末级漏极效率（DE）74.1%~79.5%的高效率输出。结果表明:对比国内外相近频率范围内的PA设计,文中提出的PA设计方法在确保宽带高效率的同时,显著缩减了电路面积,提升了结构紧凑性,为低频应用的小型化宽频带高效率PA提供了一种有效方案,在无线通信、雷达系统等领域具有潜在应用价值。

Abstract:

To address the demands of modern wireless communication systems for radio frequency (RF) power amplifiers (PAs) with high power output, broadband high efficiency, and miniaturization, this study proposes a novel design methodology for broadband high-efficiency PAs suitable for high-power output in the P/L/S bands, with a particular focus on the L band. Firstly, based on the extension of the high-efficiency impedance matching region of continuous inverse Class-F PAs and the impedance characteristics of fundamental low-pass matching circuits, a quasi-continuous inverse Class-F PA impedance model and the corresponding output circuit topology are developed. Secondly, by effectively utilizing the parasitic parameters of large-size transistors in high-power PAs and reusing fundamental and harmonic matching circuit components, the design achieves a compact high-efficiency configuration with minimal components across a wide frequency band, significantly reducing circuit complexity. Finally, to validate the proposed methodology, a prototype PA was designed using a gallium nitride high electron mobility transistor (GaN HEMT) as the primary device, targeting the 1.31.9 GHz frequency band. Experimental results demonstrate a saturated output power of 46.0146.73 dBm and a power gain of 24.0124.73 dB. Moreover, the PA achieves high-efficiency performance, with a power-added efficiency (PAE) of 65.1%69.6% and a drain efficiency (DE) of 74.1%79.5%. Compared with domestic and international PA designs within similar frequency ranges, the proposed approach ensures broadband high efficiency while significantly reducing circuit size and enhancing structural compactness. This design offers a promising solution for miniaturized, broadband, high-efficiency PAs with potential applications in wireless communication, radar systems, and related fields.