| 摘要 |
PURPOSE:To form a amplitude equalizer without delay distortion, with small circuit scale and independently of transmission speed by making variable the attenuation rate with suitably selected delay time. CONSTITUTION:Taking the input signal fed to an input terminal 101 as e<jomegat>, delay time at delay circuits 2, 5 as tau, extent of attenuation at a variable attenuation circuit 6 as alpha, and signals at connecting points 104 and 105 as A1, B1 respectively, then A1=alpha[e<jomegat>+e<jomega(t-2tau)>] and B1=e<jomega(t-tau)>, then the signal at the connecting point 106 is C1=e<jomegat>Xe<-jomegat>[1+2alphacosomegat]. Accordingly, the transfer characteristic T1(omega) from the input to the output, T1(omega)=(1+2alphacosomegatau)e<-jomegatau>. Taking the characterstics function of the amplitude, phase and delay time as S1(omega), theta1(omega), and D1(omega), then T1(omega)=S1(omega).e<jtheta1>(omega), S1(omega)=1+2alphacosomegatau, theta1(omega)=-omegatau, D1(omega)=-[alphatheta1 (omega)]/alphaomega=tau (constant). S1(omega) is changed due to the change in alpha, but theta1(omega) is independent of alpha and omega, then D1(omega) is always constant, resulting that no delay distortion is caused. |
