基于推挽式结构大功率放大器热分析

Thermal analysis of high-power amplifiers based on push-pull structures

本文为了验证大功率功率放大器在强迫风冷散热方式下的散热效果,设计了一款基于推挽式结构的大功率放大器,通过理论分析计算散热方案,使用ICEPAK散热软件仿真验证理论计算结果。考虑到功放耗散功率较大,最终采用强迫风冷和热沉的散热方式对功放进行散热。本文设计基于LDMOS功率管型号为MRF13750H,仿真设计在单频点915 MHz,输入功率35dBm时,输出功率达615W,效率为74%,耗散功率约达290 W,理论计算所需风机的风量大小为2.54 m3/min。ICEPAK软件进行仿真在耗散功率在300 W时,功率管温度为71.25℃,风机工作点为3.86 m3/min,工作静压力为201 Pa。仿真验证满足设计要求。

In order to verify the cooling effect of high-power amplifier in forced air cooling,a highpower a-mplifier based on push-pull structure was designed,the cooling scheme was calculated by theoretical analysis,and the theoretical calculation results were simulated and verified by using ICEPAK cooling software.Considering the high power consumption of the power amplifier,forced air cooling and heat sinking are adopted to dissipate the heat of the power amplifier.The LDMOS power transistor model in this paper is MRF13750H,which is simulated and designed at a single frequency of 915 MHz,with an input power of 35 dBm.The output power is 615W,the efficiency is 74%,the dissipation power is about 290W,and the required fan volume is 2.54 m3/min according to theoretical calculation.ICEPAK software simulation shows that when the dissipated power is 300 W,the power tube temperature is 71.25℃,the fan operating point is 3.86 m3/min,and the static pressure is 201Pa.