LC resonant frequency calculator

At resonance the inductive and capacitive reactances cancel and the circuit presents pure resistance.

microhenry
picofarad
ohm
Resonant frequency
1.591 549 4MHz
≈ Rounded LC resonance
Resonant frequency
1 591 549.4 Hz
Reactance at resonance
1000 ohm
Q factor
200.000
Bandwidth
7957.75 Hz
Free-space wavelength
188.365
Show the working
  1. Inductance = 100
  2. Capacitance = 100
  3. Series resistance = 5
  4. l_h = 100 * 1e-6 = 0.0001
  5. c_f = 100 * 1e-12 = 1e-10
  6. Resonant frequency = 1 / (2 * pi * sqrt(0.0001 * 1e-10)) = 1 591 550
  7. Resonant frequency = 1 591 550 / 1e6 = 1.591 55
  8. Reactance at resonance = 2 * pi * 1 591 550 * 0.0001 = 1000
  9. Q factor = 1000 / 5 = 200
  10. Bandwidth = 200 > 0 ? 1 591 550 / 200 : 0 = 7957.75
  11. Free-space wavelength = 1 591 550 > 0 ? c / 1 591 550 : 0 = 188.365

Values are shown to six significant figures here; the arithmetic itself runs on exact fractions and is only rounded where a number is printed.

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    The formula

    • f = 1 / (2 pi sqrt(L C))
    • Q = XL / R
    • bandwidth = f / Q

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