The band-pass filter is based on the interplay of the inductive and capacitive component. When comparing the behavior of a capacitor and an inductor in terms of reactance (imaginary part of the impedance) and phase angle to an applied AC signal, they behave complementary (Figure ). While the pure inductor shows a linearly increasing reactance XL with increasing frequency and a phase angle of 90°, the reactance of a capacitor XC is exponentially decaying (phase angle of pure capacitor: -90°). Therefore, at high frequencies the main voltage drop in the LC circuit occurs over the inductor while the voltage drop across the capacitor and the resistor is minimal (leading to a low Vout). At low frequencies, however, the capacitor exhibits a high reactance leading to a main voltage drop across the resistor and a low remaining voltage drop across the inductor and the resistor (leading to a low Vout).