\documentclass{scrartcl}
\usepackage{ngerman}
\usepackage[T1,OT1]{fontenc}
\usepackage[ansinew]{inputenc}
\usepackage{color}
\usepackage{multicol}
\usepackage[final]{graphicx}
\usepackage{pst-plot,pstricks}
	\input{pstplot-logarithmic-axes}
\begin{document}
	\psset{xunit=2cm,yunit=2cm}
	\begin{pspicture}(-0.5,-4.5)(5,0.5)
		\psgrid[xunit=1,yunit=1,subgriddiv=0,griddots=5,gridlabels=0](0,-4.5)(4,0.5)
		\psaxes[Dx=1,Dy=1]{->}(0,0)(-0.5,-4.5)(5,0.5)
		\psplot[linestyle=dotted]{0}{1}{x -0.5 mul}
		\psplot[linestyle=dotted]{1}{3}{x -0.5 mul 1 sub}
		\psplot[linestyle=dotted]{3}{4}{x -0.5 mul}
		\psplot{0}{1}{x -0.5 mul 1 sub}
		\psplot{1}{3}{x -0.5 mul}
		\psplot{3}{4}{x -0.5 mul 1 add}
		\psplot[linestyle=dashed]{3}{4}{x -0.5 mul 1 sub}
		\psline{->}(4.1,-3)(4.6,-2)(4.1,-1)
		\rput[l](4.7,-2){$+2\pi$}
		\rput[r](-0.1,0.4){$\frac{\Theta\left(\underline{H}\left(j\omega\right)\right)}{\pi}$}
		\rput[l](5,0){$\frac{\omega}{\frac{\omega_0}{4}}$}
	\end{pspicture}
\end{document}
