This paper presents high power, thermal analyses, and implementation of a stepped impedance high‐power low‐pass filter (LPF). A comprehensive model and analysis have been developed for the design and simulation of the LPF. In this analysis, power handling capacity and breakdown‐voltage are discussed, and the effects of critical points are considered. The attenuation due to conductor and dielectric losses is also studied. The novelty of our approach lies in employing theoretical analysis to estimate the power‐dissipation of the filter based on the proposed equivalent circuit. An accurate method is also introduced to calculate attenuation in the filter's elements. Thermal analysis to obtain accurate temperature profiles is done for the first time based on the electro‐thermal simulation. Consequently, an effective cooling method is used to spread heat across the entire filter. Finally, the filter was implemented and tested to operate at L‐band with handling 8 kW peak and 800 W average power. The insertion‐loss is less than 0.27 dB, the stop‐band attenuation is more than 60 dB, and the return‐loss is better than 15.7 dB. The filter is capable of tolerating produced heat without any destructive effects at a maximum temperature of about 200°C above ambient. The theoretical analysis and experimental results show that the LPF is suitable for high‐power microwave applications.

中文翻译：

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L波段高功率步进阻抗低通滤波器的热分析，设计和实现

本文介绍了高功率，热分析和步进阻抗高功率低通滤波器（LPF）的实现。已经为LPF的设计和仿真开发了综合模型和分析。在此分析中，讨论了功率处理能力和击穿电压，并考虑了临界点的影响。还研究了由于导体和介电损耗引起的衰减。我们方法的新颖之处在于采用理论分析来基于所提出的等效电路来估计滤波器的功耗。还引入了一种精确的方法来计算滤波器元件中的衰减。首次基于电热模拟进行热分析以获得准确的温度曲线。所以，有效的冷却方法用于将热量散布到整个过滤器上。最后，该滤波器已实现并经过测试，可在L波段工作，可处理8 kW峰值和800 W平均功率。插入损耗小于0.27 dB，阻带衰减大于60 dB，回波损耗优于15.7 dB。该过滤器能够承受产生的热量，在最高温度比环境温度高约200°C时不会产生任何破坏性影响。理论分析和实验结果表明，LPF适用于大功率微波应用。该过滤器能够承受产生的热量，在最高温度比环境温度高约200°C时不会产生任何破坏性影响。理论分析和实验结果表明，LPF适用于大功率微波应用。该过滤器能够承受产生的热量，在最高温度比环境温度高约200°C时不会产生任何破坏性影响。理论分析和实验结果表明，LPF适用于大功率微波应用。