📡 LC Resonant Frequency Calculator

Calculate LC resonant frequency, inductance, and capacitance values for tank circuits, oscillators, and filters. Design RF circuits with precise component calculations.

Calculation Type

Input Parameters

LC Resonant Frequency
f = 1 / (2π√LC)
Calculate resonant frequency from inductance and capacitance

Results & Analysis

Enter values and click Calculate to see LC circuit analysis results

LC Circuit Theory

Resonant Frequency

At resonance, inductive and capacitive reactances are equal, creating minimum impedance for series circuits.

  • f₀ = 1/(2π√LC)
  • XL = XC at resonance
  • Maximum current in series LC
  • Used in oscillators and filters

Quality Factor (Q)

Measures the sharpness of resonance and energy storage efficiency in the circuit.

  • Higher Q = sharper resonance
  • Q = f₀/BW (bandwidth)
  • Affects selectivity in filters
  • Limited by resistance losses

Applications

  • Tank Circuits: Energy storage and oscillation
  • Filters: Bandpass and notch filters
  • Oscillators: RF signal generation
  • Tuning: Radio and antenna matching

HOW TO USE

Enter the inductance (L) and capacitance (C) values. Click Calculate to find the resonant frequency, quality factor, and bandwidth of the LC circuit.

FORMULA USED

Resonant frequency: fr = 1 ÷ (2π√(L×C))
Quality factor: Q = (1/R)×√(L/C)
Bandwidth: BW = fr ÷ Q

WORKED EXAMPLE

L = 10mH, C = 100μF: fr = 1 ÷ (2π × √(0.01 × 0.0001)) = 159.2 Hz.

FREQUENTLY ASKED QUESTIONS

Q: What is LC resonance?

A: At resonance, inductive reactance equals capacitive reactance (XL = XC). The circuit has minimum impedance in series or maximum in parallel.

Q: What is quality factor (Q)?

A: Q factor measures the sharpness of resonance. High Q means sharp, selective frequency response. Q = Energy stored ÷ Energy dissipated per cycle.

Q: What is bandwidth of an LC circuit?

A: Bandwidth is the range of frequencies around resonance where power is at least half the maximum: BW = fr ÷ Q.

Q: Where are LC resonant circuits used?

A: Radio tuning circuits, bandpass filters, oscillators, wireless power transfer, and impedance matching networks.