## Microstrip PCB Impedance Calculator

Microstrip are transmission lines that are routed on the external layers of the PCB which are always routed above a large reference plane on the adjacent layer. As the name suggests microstrip lines are used to convey microwave-frequency signals and RF signals. You can read more about microstrip here.

Calculate the impedance, capacitance, propagation delay, and inductance of a Microstrip Line PCB using this convenient online calculator. Understand the characteristics of your electrical transmission lines and optimize your circuit design.

**Formula**

\[Z = \frac{87}{\sqrt{e_r+1.41}} * ln \left(\frac{5.98h}{0.8w + t}\right) \]\[ P = 3.333 * \sqrt{0.475e_r + 0.67} * dimension\]\[C = \frac{P}{Z} \]\[ R = \frac {17.2}{w * t * dimension^2} * 1000 \]\[ L = \frac {P * Z}{1000} \]

**where** :

- Z = Single Ended Impedance
- e
_{r}= Relative dielectric constant - h = Trace width
- w = Trace height
- t = Trace thickness
_{P}= Propagation Delay- C = Capacitance
- L = Inductance
- R = Resistance
- If the dimension unit is mm then dimension=1
- If the dimension unit is mils then the dimension is 0.0254

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