Passive Components

Created: 05/09/2020Last Update: 07/06/2023


Resistors, capacitors, and inductors are fundamental components used for filtering and energy storage in electronic circuits. Resistors impede current flow, while capacitors and inductors store energy in electric and magnetic fields, respectively. Resistors are classified as real components, while capacitors and inductors are reactive components.


Several important terms and characteristics are relevant to circuit modeling and frequency analysis:

Resistor: Characteristics:

Capacitor: Characteristics:

Inductor: Characteristics:






Q: What can be used to shunt ESD energy? 

A: To shunt ESD energy from the antenna, an RF shunt inductor placed near the antenna is effective. Since ESD currents typically occur in the tens of MHz range, the RF shunt inductor provides a low impedance path for the ESD energy to be directed to the ground.

Q: How can ESD energy from a connector be shunted? 

A: To shunt ESD energy coming from a connector, a 0.1 uF ceramic shut capacitor placed near the connector can be used. ESD or transient voltages generally have a spectrum in the tens of MHz range, and small ceramic capacitors offer low impedance at this frequency, providing an efficient path for ESD energy to be directed to the ground.

Summary & Conclusion

Understanding their non-ideal effects helps engineers choose the right components for their designs.

Further Reading

"Capacitor Guide", 

"Basic Factors about inductors",