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通过对叠加窄带噪声的确定的正弦波信号输入到非线性放大器时的输出信噪比进行广泛研究表明,在输入信噪比大时,通过限幅器,当输入信噪比小时,在非高斯噪声情况下,通过乘幂放大器往往可以改善输出信噪比。本文将具有饱和特性的乘幂形非线性放大器的输入—输出特性,用5次幂多项式表示,首先,导出对窄带高斯噪声和窄带非高斯噪声都能适用的信噪比改善率的一般表达式,接着,通过数值计算研究了输出信噪比随输入信噪比的变化。结果表明,这种非线性放大器,在输入信噪比大时近似于软限幅,在输入信噪比小时近似于乘幂放大器,对于非高斯噪声,输入信噪比在除0dB附近以外的全部范围内,输出信噪比往往得到改善。
Extensive research on the output signal-to-noise ratio (SNR) of a given sine wave signal superimposed with narrow-band noise on a non-linear amplifier shows that when the input signal to noise ratio is large and the input SNR is small, In the case of noise, the output signal-to-noise ratio can often be improved by exponentiation amplifiers. In this paper, the input-output characteristics of power amplifier with exponentials of saturation are represented by 5 power polynomials. First, the general expression of signal-to-noise ratio improvement rate applicable to both narrow-band Gaussian noise and narrow-band non-Gaussian noise Then, the change of output signal-to-noise ratio with input signal-to-noise ratio is studied by numerical calculation. The results show that this kind of nonlinear amplifier approximates the soft limit when the input signal to noise ratio is large and approximates the power amplifier when the input signal to noise ratio is small. For non-Gaussian noise, the input signal to noise ratio is all except 0dB Within the range, the output signal to noise ratio tends to be improved.