2.2 High Pass Filter

These types of filters allow high frequencies to pass through it and block the lower frequencies. The figure 2.6.7 shows circuitry forhigh pass filter.

Figure 2.6.7 Circuitry of High Pass Filter

 

Figure 2.6.8 Pass band for high pass filter

(2.6.9)

 

(2.6.10)

From equation 2.6.10, we can say that if frequency of input signal is low then would be high and thus would be nearly equal to 0. For high frequency signal, would be low and would be nearly equal to 1. Thus above circuit will act as High Pass Filter.It selects frequencies above a breakpoint frequency ω = 1/RC as shown in Figure 2.6.8. By selecting suitable values of R and C we can allow desired (high) frequency level to pass through.