Bandwidth

Definition

Bandwidth in an AC circuit refers to the range of frequencies over which the circuit can effectively operate. It is typically defined as the difference between the upper and lower frequency limits where the circuit's performance remains within acceptable levels.

5 Must Know Facts For Your Next Test

1. The bandwidth is determined by the resonant frequency and the quality factor (Q) of the circuit.
2. A narrow bandwidth indicates a high Q factor, meaning the circuit is highly selective for its resonant frequency.
3. In a series RLC circuit, bandwidth can be calculated using $\Delta f = \frac{R}{2\pi L}$.
4. The half-power points, or -3 dB points, mark the frequencies at which power falls to half its maximum value.
5. Bandwidth is inversely proportional to the quality factor: $BW = \frac{f_0}{Q}$, where $f_0$ is the resonant frequency.

Review Questions

• What is the relationship between bandwidth and quality factor in an AC circuit?
• How do you calculate bandwidth in a series RLC circuit?
• What are half-power points and why are they important for determining bandwidth?

Related terms

Resonant Frequency: The frequency at which an AC circuit's impedance is at a minimum and current reaches its maximum.

Quality Factor (Q): A dimensionless parameter that describes how underdamped an oscillator or resonator is, related to its bandwidth.

Half-Power Points: Frequencies at which power drops to half of its peak value; used to determine bandwidth.