Experiement -2-Time Domain Response of HPF. Part 2
2.4. High pass RC circuit .
Figure 2 .c. Square Wave Response of High Pass Filter for T ~ τ .
Figure 2 .d. Square Wave Response of High Pass Filter for T<<τ .
When T<<τ then the frequency spectrum of the square wave lies well within the Pass Band of the High Pass Filter. Hence the input square wave is near faithfully transmitted to the output except for a sag at the top and bottom and there is the loss of OFFSET.
The BW of HPF is from (1/τ) = ω L radians per sec to infinity.
The spectral components of the square wave are 0Hz, (1/T)Hz, (3/T)Hz,………
Since 1/T>>(1/(2πτ)), hence (1/T)Hz, (3/T)Hz,……… are well accommodated and faithfully transmitted by HPF but 0Hz gets completely suppressed. Hence we get a Square Wave with ZERO mean value and TOP and BOTTOM have sag.