The selection characteristics of series resonant circuits and parallel resonant circuits have opposite properties. The frequency dependence of input current/(ω) for series and parallel circuits with the same resonant frequency and close Q factor is qualitatively presented in the figure.
A series resonant circuit can transmit signals at and near the resonant frequency, and delay signals at other frequencies. Parallel circuits will delay the resonant frequency and approach it, and are "transparent" to signals in other frequency ranges. Similar to the bandwidth of serial circuits used for parallel circuits in radio engineering, the concept of stopband or notch is employed. A parallel resonant circuit with a high Q-factor is called a suppressor.
The series resonant and parallel resonant circuits considered are the simplest resonant circuits with frequency selective characteristics. In order to obtain a more obvious
Qualitative view of the frequency dependence of input current/(ω) in a resonant circuit:
A resonant circuit (coupling circuit) that maintains consistency, uses parallel selection of mass, and includes inductive coupling coils in frequency, using more complex circuits.