Design with PIN DiodesAPPLICATION NOTE APN1002: Design With PIN Diodes The PIN diode finds wide usage in RF, UHF and microwave circuits. It is fundamentally a device whose impedance, at these frequencies, is controlled by its DC excitation. A unique feature of the PIN diode is its ability to control large amounts of RF power with much lower levels of DC. Area A P+ W PIN Diode Fundamentals The PIN diode is a current controlled resistor at radio and microwave frequencies. It is a silicon semiconductor diode in which a high-resistivity intrinsic I region is sandwiched between a P-type and N-type region. When the PIN diode is forward biased, holes and electrons are injected into the I region. These charges do not immediately annihilate each other; instead they stay alive for an average time, called the carrie……