用汉宁窗函数法设计一个数字FIR高通滤波器，要求通带边界频率为500Hz，阻带边界频率为400Hz，通带最大衰减1dB，阻带最小衰减40dB，抽样频率为2000Hz，用MATLAB画出幅频特性，画出并分析滤波器传输函数的零极点-With han ning window function method to design a digital FIR high-pass filter, request bandpass boundary frequency for 500 Hz, stop-band boundary frequency for 400 Hz, bandpass biggest 1 dB attenuation, stop-band attenuation least 40 dB, sampling frequency for 2000 Hz, MATLAB draw the amplitude frequency characteristics, painted and analysis filter transmission function of zero poles