Читать книгу Inverse Synthetic Aperture Radar Imaging With MATLAB Algorithms - Caner Ozdemir - Страница 79

%--------------------------------------------------------- % This code can be used to generate Figure 2.16 %--------------------------------------------------------- clear close all t=0:0.01e-9:50e-9; % choose time vector N=length(t); pulse(201:300)=ones(1,100); % form rectangular pulse pulse(N)=0; % Frequency domain equivalent dt=t(2)-t(1); % time resolution df=1/(N*dt); % frequency resolution f=0:df:df*(N-1); % set frequency vector pulseF=fft(pulse)/N; % frequency domain signal %---Figure 2.16(a)------------------------------------------ plot(t(1:501)*1e9,pulse(1:501),'k','LineWidth',2); grid minor set(gca,'FontName', 'Arial', 'FontSize',12,'FontWeight','Bold'); xlabel('\ittime, ns'); ylabel('\itamplitude, V'); axis([0 5 0 1.1]); %---Figure 2.16(b)------------------------------------------ figure plot(f(1:750)/1e9,20*log10(abs(pulseF (1:750))),'k','LineWidth',2); grid minor set(gca,'FontName', 'Arial', 'FontSize',12,'FontWeight','Bold'); axis([0 f(750)/1e9 -85 -20]); xlabel('\itfrequency, GHz'); ylabel('\itamplitude, dB');