\documentclass{scrartcl}
\usepackage{color}
\usepackage{multicol}
\usepackage[final]{graphicx}
\usepackage{pst-plot,pstricks}
	\input{pstplot-logarithmic-axes}
\begin{document}
	\psset{xunit=3cm,yunit=0.1cm}
	\begin{pspicture}(-3,-50)(3,20)
		\psgrid[xunit=0.5,yunit=10,subgriddiv=0,griddots=5,gridlabels=0](-4,-4)(4,1)
		\psaxes[log=x,Dx=5,Dy=10]{->}(-2,0)(-2,-40)(2.2,11)
		\psplot[plotstyle=curve]{-2}{2}{-20}
		\psplot[plotstyle=curve,linecolor=red]{-2}{0}{0}
		\psplot[plotstyle=curve,linecolor=red]{0}{1}{x 20 mul}
		\psplot[plotstyle=curve,linecolor=blue,linestyle=dashed]{-2}{1}{0}
		\psplot[plotstyle=curve,linecolor=blue,linestyle=dashed]{-1}{1}{x 1 add -20 mul}
		\psplot[plotstyle=curve,linecolor=blue,linestyle=dashed]{1}{2}{x 1 sub -20 mul}
		\rput(2,3){$\omega$}
		\rput(-2,14){$\frac{\left|\underline{H}\left(j\omega\right)\right|}{dB}$}
	\end{pspicture}
\end{document}