Denote a zero mean

1. Let W(t) denote a zero mean white noise process with power spectral density No/2 Watts/Hz. The process is passed through an ideal lowpass filter with transfer function H(f) = J 1, If SB 0, otherwise. Let Y (t) denote the output of the filter. a) What is the autocorrelation function of the white noise process W(t)? b) Is the output process Y(t) wide-sense stationary? Explain. c) What is the power spectral density of Y(t)? d) Find and plot the autocorrelation function of the output process Y(t)? e) Find the power Py of the process Y (t). f) Find the covariance cov(Y (t), Y(t + 2/B)).Consider an n-type semiconductor with ND = 10 em . There is a uniform applied electric field, E = 10 V / em, throughout the semiconductor. At t = 0, the semiconductor was illuminated by a sharply focused pulse of laser to create an excess hole concentration of Ap(t = 0) = 102cm at x = 0. Find the expression for the excess hole concentration, Ap(a, t), as a function of x and t fort > 0, i.e. after the laser pulse is gone. Write your expression in terms of applied electric field, E, generation rate G, minority carrier lifetime, T, diffusion coefficient, D and mobility, A. Subscript p can be omitted for simplicity