1. What is Characteristic Impedance?

Characteristic impedance (Z₀) is the ratio of voltage to current in a transmission line with no reflections (infinite or perfectly terminated line). It's determined by the geometry and materials of the transmission line.

2. How Does the Calculator Work?

The calculator uses the characteristic impedance formula:

Where:

• \( Z_0 \) — Characteristic impedance (Ω)
• \( L \) — Inductance per unit length (H/m)
• \( C \) — Capacitance per unit length (F/m)

Explanation: The formula shows that characteristic impedance depends on the square root of the ratio of inductance to capacitance per unit length of the transmission line.

3. Importance of Characteristic Impedance

Details: Matching characteristic impedance is crucial for maximum power transfer and minimizing reflections in transmission lines. Common values include 50Ω (RF systems) and 75Ω (video systems).

4. Using the Calculator

Tips: Enter inductance and capacitance per unit length values. Both must be positive numbers. The calculator will compute the characteristic impedance in ohms (Ω).

5. Frequently Asked Questions (FAQ)

Q1: What are typical characteristic impedance values?
A: Common values are 50Ω for RF systems, 75Ω for video systems, and 100Ω for twisted pair Ethernet cables.

Q2: Why is impedance matching important?
A: Impedance matching minimizes signal reflections and ensures maximum power transfer between components.

Q3: How does frequency affect characteristic impedance?
A: For ideal transmission lines, Z₀ is frequency-independent. In real lines, it may vary slightly with frequency.

Q4: What happens when impedances don't match?
A: Signal reflections occur, leading to standing waves and reduced power transfer.

Q5: Can this formula be used for all transmission lines?
A: This is the basic formula. Some transmission line geometries may require more complex calculations.