Silicon Diodes are electronic components that conduct current in only one direction. In function, they are similar to one-way valves. Silicon Diodes are manufactured using semiconductor materials such as silicon, germanium or selenium and are used as voltage regulators, signal rectifiers, oscillators and signal modulators, demodulators.

Semiconductor diodes consist of a PN junction having two terminals, an anode (+) and a cathode (-). Current flows from the anode to the cathode within the diode. Diodes can be used as voltage regulators, tuning devices in RF tuned circuits, frequency multiplying devices in RF circuits, mixers in RF circuits, switching applications, or can be used to make logic decisions in digital circuits.
Diodes can be sub-divided into six major categories:

• General purpose diodes or PN junction diodes
• PIN diodes
• Schottky barrier diodes
• Step-recovery diodes
• Varactor diodes
• Zener diodes