Diagram of pin diode. Often the diodes are spaced apart by the magic quarterwave to improve small signal response. The diode has a large intrinsic region between the n and p region which can tolerate the high reverse voltage. The pin diode is used as a high voltage rectifier. Photo detector the pin diode is used for converting the light energy into the electrical energy.
Pin diodes can also be used to create limiters a type of nonlinear device usually as one or more shunt elements across a transmission line. A pin diode is a current controlled device in contrast to a varactor diode which is a voltage controlled device. The pin diode is used as an ideal radio frequency switch. The diode has large depletion region which improves their performance by increasing the volume of light conversion.
The pin diode found its first applications in 1952 as a low frequency high power rectifier. Varactors diodes are design with thin epitaxial i layers for a high q in the reverse bias and little or no concern for carrier lifetime stored chargewhen the forward bias control current of the pin diode is varied continuously it can be used for attenuating leveling. Since such a diode is sensitive to light the use as a nuclear. Pin diode counter bernd laquai 492012 the bpw34 pin diode the most legendary pin diode which is also used as a nuclear radiation detector is the bpw34.
The intrinsic layer among the p n layers increases the space between them. The p type and n type regions are typically heavily doped because they are used for ohmic contacts. It is available from several semiconductor manufacturers in different variants and was originally designed for visible and invisible wavelength up to the ir wavelength region. The pin diode is very good for rf switching and the pin structure is also very useful in photodiodes.
This also reduces the capacitance between both the regions thus raising the level of isolation when the pin diode is reverse biased.