Switching Semiconductor Diode

a semiconductor diode for controlling the power level of microwave transmission lines. It is used in various switches, electrically controlled attenuators, modulators, phase shifters, and other devices.

The existing types of such diodes include diodes having a p-n junction; diodes with a metal-semiconductor contact, or Schottky barrier diodes; diodes with a p-i-n structure, which are the most common; and diodes with a metal-dielectric-semiconductor structure. The action of switching semiconductor diodes is based on the dependence of the electrical impedance on the applied voltage. For example, when a DC bias current of ~ 0.1 ampere flows through a silicon switching semiconductor diode that has a p-i-n structure, the diode is circuitwise equivalent to a resistor of ≤ 1 ohm; but with a reverse bias or no bias it is equivalent to a capacitor of 0.1 to 1 picofarad in series with a resistance of ~ 1 ohm. By comparison with electromechanical apparatus and apparatus involving ionic devices, apparatus with a switching semiconductor diode has a very small size, low weight, improved reliability, and faster response—the speed of response ranges from several nanoseconds to several microseconds. Switching semiconductor diodes are promising for integrated circuits.