# PCB Calculator

Microstrip is a type of electrical transmission lines which can be fabricated using printed circuit boards (PCB). Impedance in an electrical circuit is the complex ratio of the voltage to the current. Propagation delay is the amount of time which takes for the head of the signal to travel from the sender to the receiver. The below PCB Calculator helps you to calculate the impedance, capacitance, propagation delay and inductance of a Microstrip Line PCB .

## Microstrip Line Calculator | Microstrip PCB Impedance Calculation

Microstrip is a type of electrical transmission lines which can be fabricated using printed circuit boards (PCB). Impedance in an electrical circuit is the complex ratio of the voltage to the current. Propagation delay is the amount of time which takes for the head of the signal to travel from the sender to the receiver. The below PCB Calculator helps you to calculate the impedance, capacitance, propagation delay and inductance of a Microstrip Line PCB .

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#### Formula:

z = 87 / √(e + 1.41) × LN((5.98 x h) / (0.8 x w + t))
c = (2.64 x 10^{-11}) x (e + 1.41) / (LN((5.98 x h) / (0.8 x w + t)))
p = (3.34 x 10^{-9}) x √(0.475 x e + 0.67)
l = c x z^{2}
**Where,**
z = Characteristic Impedance
e = Relative Permittivity
h = Height of Dielectric
w = Width of Trace
t = Trace Thickness
c = Capacitance per unit length
p = Effective propagation delay
l = Inductance per unit length
### Example

Consider a PCB microstrip line trace of 15 cm width and 5 cm thickness with a relative permittivity of 23 and dielectric height as 12 cm.

#### Characteristic Impedance

z= 87 / √(23 + 1.41) × LN((5.98 x 12) / (0.8 x 15 + 5))

= 25.359 ohm

#### Capacitance Per Unit Length

c= (2.64 x 10^{-11}) x (23 + 1.41) / (LN((5.98 x 12) / (0.8 x 15 + 5)))

= 4.4748 x e^{-10}F/m

#### Effective Propagation Delay

p= (3.34 x 10^{-9}) x √(0.475 x 23 + 0.67)

= 1.1953e^{-8}s/m

#### Inductance per unit length

l= 4.4748 x e^{-10} x (25.359)^{2}

= 2.877 H/m
Microstrip PCB Impedance in an electric circuit causes an electromotive force to be generated by a change in the current flowing. Capacitance is the capacity of an electric circuit to store an electric charge. In this PCB calculator, microstrip line of capacitance per unit length is expressed in F/m.