Tunable LC Resonance

Application

Use this circuit as a simplified adjustable RF coil or tuned-filter example.

Design Context

A source and series resistor excite a shunt LC tank so the resonant response appears at Vtank.

Expected Behavior

The AC response changes as the variable component setting changes, shifting the resonant feature.

Key Values

• R1 is 1 k.
• C1 is 47 nF.
• LV1 ranges from 1 mH to 20 mH.

Suggested Experiments

• Change the position setting and rerun the sweep.
• Adjust R1 to change damping.
• Compare the resonant frequency against the LC estimate.

Featured Component

The variable inductor tunes the tank inductance without rewiring the circuit.