Interdigital Capacitor Calculator

This page provides an interdigital capacitor calculator.

EXAMPLE #1:

• INPUTS:
  • Dielectric constant = 9.8
  • Number of fingers = 10
  • Finger length = 0.0025 cm
  • Finger width = 0.05 cm
• OUTPUT:
  • Capacitance = 0.4 pF/cm

EXAMPLE #2:

• INPUTS:
  • Dielectric constant = 13
  • Number of fingers = 10
  • Finger length = 0.001 inch = 0.001 * 2.54 cm
  • Finger base width = 0.02 inch = 0.02 * 2.54 cm
• OUTPUT:
  • Capacitance = 0.51 pF/cm

Interdigital Capacitor Equation

As shown in the figure and the equation below, constructing an interdigital capacitor doesn’t require any complicated processes. It’s quite similar to MIC (Microwave Integrated Circuit) technology.

The capacitance value of this type of capacitor hinges on the W/L ratio (width to length), the gap distance ‘d’ between the two conductors, and the number of fingers, denoted as N.

The following equation or formula is used for the Interdigital capacitor calculator: