LC Tank Circuit Calculator: RF Tuning & Filtering

A Radio Frequency (RF) tank circuit is a fundamental component used in RF electronic circuits for tuning and filtering purposes. It consists of inductors (L) and capacitors (C) arranged in a specific configuration to resonate at a particular frequency.

Explore the tank circuit calculator and learn about LC tank circuit basics and its resonant frequency formula. In an RF tank circuit, the inductor and capacitor are often connected in parallel or in series. The RF signal to be tuned or filtered is applied to this tank circuit. When the frequency of the input signal matches the resonant frequency of the tank circuit, the circuit becomes highly reactive, and the impedance of the tank circuit becomes maximum. This means the circuit will absorb maximum energy from the input signal at that frequency.

LC Tank Circuit Examples

Here are a couple of examples demonstrating how the LC tank circuit calculator works:

EXAMPLE #1:

• INPUTS:
  • L = 10e-3 Henrys (i.e. 10nH)
  • C = 100e-6 Farads (i.e. 100 µF)
• OUTPUT:
  • Tank circuit resonance frequency (Fr) = 0.0001591 MHz or 159.1Hz

EXAMPLE #2:

• INPUTS:
  • L = 100 Henrys
  • C = 10 Farads
• OUTPUT:
  • Fr = 5.03e-9 Hz
  • Fr = 0.00503 Hz

Applications of RF Tank Circuits

RF tank circuits have numerous applications, including:

• Tuning Circuit: RF tank circuits are used in tuning circuits of radios, televisions, and transmitters. By adjusting the values of the inductor or capacitor, the resonant frequency of the tank circuit can be changed, allowing different frequencies to be tuned.

• Filtering: RF tank circuits can be used as bandpass or band-stop filters in RF systems, allowing specific frequencies to pass through while attenuating others.

Resonant Frequency Formula for LC Tank Circuits

When an inductor and a capacitor are connected in parallel or in series, they form a resonant circuit. This resonant circuit can store energy at a specific frequency. The resonance frequency is determined by the values of the inductor and capacitor.

The following resonant frequency formula is used in this calculator to calculate the resonance frequency of an LC tank circuit:

In the equation:

• ‘Fr’ is the resonant frequency in Hertz (Hz).
• ‘L’ is the inductance in Henry (H).
• ‘C’ is the capacitance in Farad (F).
• ‘pi’ is a mathematical constant (Approximately 3.14159)

Conclusion

Overall, RF tank circuits play a crucial role in RF circuit design, enabling tuning and filtering of signals at specific frequencies. They are essential components in various RF systems, including communication devices, transmitters, receivers, and antennas.

There are other types of tank circuits in electronics, each serving different purposes. The popular among them are audio tank circuit, Tesla Coil tank circuit, MRI (Magnetic Resonance Imaging) tank circuit, LC oscillator tank circuit, LC filter tank circuit, and RLC tank circuit.