What is the relationship between capacitance and reverse bias voltage in an abrupt junction varactor diode?

Generally, the depletion region thickness is proportional to thehttp://www.answers.com/topic/square-root of the applied voltage; and http://www.answers.com/topic/capacitanceis inversely proportional to the depletion region thickness. Thus, the capacitance is inversely proportional to the square root of applied voltage.