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📡 RC Frequency Filters

Bode magnitude plot · Adjust R and C · Switch filter type · See input vs output signals

Filter Type

RC Parameters

Test Signal

Filter Info

f_c (cutoff) —
ω_c (rad/s) —
|H| at f —
Attenuation —

Formula

Low-pass:
τ = RC
|H| = 1/√(1+(ωτ)²)
f_c = 1/(2πRC)

📻 RC Frequency Filters — Bode Plot

Interactive RC filter simulation. Switch between low-pass, high-pass and band-pass modes. Adjust resistance and capacitance to see the Bode plot, cutoff frequency and signal attenuation update live.

🔬 What It Demonstrates

An RC filter's cutoff frequency f_c = 1/(2πRC) defines where the output drops by 3 dB (~70.7% of input). Below f_c, a low-pass filter passes signals unchanged; above, it attenuates at −20 dB/decade. High-pass does the reverse.

🎮 How to Use

Select filter type (LP/HP/BP). Drag resistance and capacitance sliders. The Bode magnitude plot shows the frequency response. The −3 dB marker moves with the cutoff. Input and output signals compare live.

💡 Did You Know?

Every audio equaliser, radio tuner and power supply uses RC filters. The simplest low-pass filter — a resistor and capacitor — is the same circuit that smooths the ripple in a DC power supply rectifier.