A diode is a semiconductor device through which current supplies in one direction only. The initial diodes were crystal diodes which are used as rectifiers in radio kits. In this diode, a weak signal was fed into the crystal material using a very fine wire namely the cat's whisker. The crystal material in the diode removes the high-frequency carrier signal of radio by allowing the elements of the signal through the audio data to approach through clear. The crystal material was packed with … [Read more...]

The concept of IMPATT diode was actually invented in the year 1954 by William Shockley. So, he expanded the idea for producing a negative resistance with the help of a mechanism like transit time delay. He proposed the injection technique for charge carriers within a PN junction is forward biased and published his thought in the Technical Journal of Bell Systems in 1954 and titled with the name 'Negative Resistance Occurring from Transit Time within Semiconductor Diodes. Further, the proposal … [Read more...]

We know that there are different types of diodes are used in different applications based on the requirement like Varactor diode, Schottky diode, LED, Zener diode, etc. Even though, the most popular diode including a basic PN- junction is also used in different circuits which are called a PIN diode. As compared with a normal PN junction diode, this kind of diode is different because this diode includes three layers like P, I & N whereas the PN junction diode includes two layers like P & … [Read more...]

In GaAs semiconductor materials, the electrons are present in two states like high mass low velocity & low mass high velocity. By the demand of an adequate electric field, the electrons are forced to move from a low mass state to a high mass state. At this specific state, electrons can form a group & moves at a consistent rate that can cause to flow current in a series of pulses. So this is known as Gunn Effect which is used by Gunn diodes. These diodes are the best and most frequently … [Read more...]