Pulse and Digital Circuits

2.2 HIGH-PASS CIRCUITS

Figures 2.2(a) and 2.2(b) represent high-pass RC and RL circuits, respectively.

FIGURE 2.2(a) A high-pass RC circuit

Consider the high-pass RC circuit shown in Fig. 2.2(a). The capacitor offers a low reactance (X_C = 1/jωC) as the frequency increases; hence, the output is large. Consequently, high-frequency signals are passed to the output with negligible attenuation whereas, at low frequencies, due to the large reactance offered by the condenser, the output signal is small. Similarly, in the circuit shown in Fig. 2.2(b), the inductive reactance X_L (= jωL) increases with frequency, leading to a large output. At low frequencies, ...