基于分段曲线拟合的短波功放频响校正方法

摘要

针对短波功率非线性引起的增益不平坦问题,提出了一种分段曲线拟合的频响校正方法.先根据离散数据信息人为分为若干段,再离线拟合多段曲线以逼近原始数据.通过设计多段频响校正滤波器函数,实现整个频段内的实时补偿,以获得功放的稳定输出.搭建基于DSP+FPGA硬件平台,在短波电台上实测数据,表明提出的方法可有效拟合原始量测数据分布,较大地改善了输出功率的平坦度和稳定性,可在工程应用中实现且效率较高.%Aimed at the deficiency of gain flatness caused by the nonlinearity of shortwave amplifier,a frequency response calibration method based on piecewise curve-fitting is proposed.Firstly,discrete data is divided into several pieces artificially and empirically.And then,the original data is approximated with piecewise curve-fitting offline.Finally,real-time compensation is executed with the whole working frequency range by designing several calibrating filter functions to obtain the stable output for the power amplifier.With the hardware platform based on DSP and FPGA,the measurement on the short-wave radio station is achieved.The practical testing data shows that the proposed method can effectively fit the original data distribution and greatly improve the flatness and stability of output power.Moreover,it can be realized in practical applications and is also fairly efficient.