Varactor Diode Calculator

This calculator calculates the capacitance of a varactor diode, its cut-off frequency and the quality factor.
  • Diode Capacitance (Cd) at 0 V
    pF
  • Barrier voltage (Vb)
    V
  • Applied reverse bias potential (V)
    V
  • Series resistance (Rs)
    Ohm
  • Operating Frequency (f)
    MHz
  • m factor
  • Calculate Reset

Result

  • Diode Capacitance (farads)
  • Cutoff frequency (MHz)
  • Quality Factor
Click here to view image

Where,

C= Diode Capacitance (at 0V)

k = 1

V= Barrier potential/voltage

V = Applied reverse bias potential/voltage

m = constant (i.e. material dependent)

Rs = Series resistance

F =  Cutoff frequency

f = Operating frequency

Q = Quality Factor

 

Example:

Cd at 0V = 90 pF, V = 0.52V, V = -5V, Rs = 14 Ohm, Operating frequency = 60 MHz, m factor = 0.5

Diode capacitance = 38.30 V, cutoff frequency = 296.92 MHz, Quality factor = 4.94