Contents
How does a PIN diode switch work?
A PIN diode behaves as a current-controlled resistor at radio and microwave frequencies. Like the conventional PN diode, it allows current flow in one direction when forward biased, but not in the other when it is reverse biased.
How do you use a PIN diode?
A PIN diode operates under what is known as high-level injection. In other words, the intrinsic “i” region is flooded with charge carriers from the “p” and “n” regions. Its function can be likened to filling up a water bucket with a hole on the side. Once the water reaches the hole’s level it will begin to pour out.
What Is PIN diode switch?
A: The PIN diode is a special diode which can be configured as an RF switch. It has a wide, undoped intrinsic semiconductor region (“I”) sandwiched between a p-type semiconductor (“P”) and an n-type semiconductor region (“N”), hence the PIN designation. This is unlike a standard diode which has no intrinsic region.
When PIN diode is used as a switch?
forward bias characteristic. If the forward current through the diode is near the maximum the diode is designed for, it typically has an RF resistance of only 0.1 ohm, and thus acts as a closed switch. Thus, for RF, the PIN diode acts as a closed switch if it is forward biased with the near maximum DC bias current.
What Is PIN diode used for?
The PIN diode is used as a photo detector to convert the light into the current which takes place in the depletion layer of a photo diode, rising the depletion layer by inserting the intrinsic layer progresses the performance by increasing the volume in where light change occurs.
How are PIN diodes used in series mode?
Figure 4: PIN diodes used in series mode for a) a basic SPST switch and b) an SPDT switch, where VG is the RF generator voltage. (Source: Skyworks Solutions, Inc.) Similarly, shunt-diode switches can be used for basic SPST and SPDT functions (Figure 5).
Why do you need DC bias on a PIN diode?
The DC bias voltage needed to control the PIN diode’s mode is a function of the diode as well as the RF signal level, temperature range, and other factors. This bias voltage must be decoupled from the RF signal and be stable, as any noise or ripple will affect the diode’s operating point.
What makes a Microsemi PIN diode so reliable?
In addition, the PIN diode has the ability to control large RF signal power while using much smaller levels of control power. Microsemi PIN diodes offer a unique highly reliable package due to voidless construction, metallurically bonded pin structure, and an extremely rugged SOGO surface passivation.
Can a PIN diode be used as a shunt?
Using either a shunt or series topology, it is challenging to achieve better than 40 dB isolation using a single PIN diode, especially at the higher operating frequencies. These limitations can be overcome somewhat by using combinations of series and shunt diodes in what are called compound switches.