This letter proposes a multifrequency impedance matching broadband power amplifier (PA) design, which is different from the traditional PA impedance value changes with the change in the operating frequency. This method selects the impedance value of the transistor device through the load–pulling system. Then, matching networks composed of a cascade of microstrip lines are used to match the device impedance to 50 $\Omega $ . The matching networks are optimized to provide the desired impedance transfer characteristic at multiple frequencies. This design approach effectively reduces the amplifiers’ output impedance variation over the covered frequency range. The overall structure of the PA is simple, and the bandwidth is expanded while ensuring performance. Based on this method, a broadband PA was designed and fabricated using the self-developed laterally-diffused metal-oxide semiconductor (LDMOS) transistor of the Institute of Microelectronics of the Chinese Academy of Sciences. The measurement results show that the saturated output power of the designed PA in the range of 0.5–2.3 GHz is greater than 41 dBm. The drain efficiency is 43.62%–55.38%. When the average output power is 34.3 dBm, the adjacent channel leakage ratio (ACLR) is also better than −31.58 dBc.

中文翻译：

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具有多频阻抗匹配的宽带功率放大器

这封信提出了一种多频阻抗匹配宽带功率放大器（PA）设计，它不同于传统的PA阻抗值随工作频率的变化而变化。该方法通过负载牵引系统选择晶体管器件的阻抗值。然后，使用由级联微带线组成的匹配网络将器件阻抗匹配到 50 $\欧米茄$ . 匹配网络经过优化，可在多个频率下提供所需的阻抗传递特性。这种设计方法有效地降低了放大器在覆盖频率范围内的输出阻抗变化。PA整体结构简单，在保证性能的同时扩大了带宽。基于此方法，利用中科院微电子所自主研发的横向扩散金属氧化物半导体（LDMOS）晶体管设计制造了宽带功率放大器。测量结果表明，所设计的PA在0.5~2.3 GHz范围内的饱和输出功率大于41 dBm。漏极效率为 43.62%–55.38%。当平均输出功率为 34.3 dBm 时，邻道泄漏比 (ACLR) 也优于 −31.58 dBc。