Applications Of PIN Diodes

By Avago Technologies

The most important property of the PIN diode is the fact that it can, under certain circumstances, behave as an almost pure resistance at RF frequencies, with a resistance value that can be varied over a range of approximately 1 Ω to 10 KΩ through the use of a DC or low frequency control current.

When the control current is varied continuously, the PIN diode is useful for leveling and amplitude modulating an RF signal. When the control current is switched "on" and "off" or in discrete steps, the device is useful for switching, pulse modulating, attenuating, and phase shifting of an RF signal.

In addition, the PlN's small size, weight, high switching speed, and minimized parasitic elements make it ideally suited for use in miniature, broadband RF signal control components.

This article describes the important properties of the PIN diode and illustrates how it can be applied in a variety of RF control circuits.