Analysis of Frequency Response with PSpice and PROBE
PSpice can readily accomplish the circuit analysis as a function of frequency, and PROBE can display Bode plots for magnitude and phase of network transfer functions. Besides the linear (LIN) frequency sweep that we used in steady-state sinusoidal analysis, with a similar syntax statement, a logarithmic frequency sweep, with points specifying the number of points per octave (an octave represents a twofold increase in frequency) or per decade (a decade represents a tenfold increase in frequency), can be specified. For example, the statement
• AC DEC 20 10HZ 1MEGHZ
requests frequency analysiswith 20 points per decade,which is usually a suitable value, starting at 10Hz and ending at 1MHz.Note that the frequencieswould be uniformly spaced on a logarithmic frequency scale.