Advantages of IMPATT diode | disadvantages of IMPATT diode
This page covers advantages and disadvantages of IMPATT diode. It mentions IMPATT diode advantages or benefits and IMPATT diode disadvantages or drawbacks.
What is IMPATT diode?
It is a two terminal semiconductor negative conductance device. It works based on principles of two phenomena viz. avalanche multiplication and transit time effects. It is the short form of Impact Ionisation Avalanche Transit Time. It is basically improved version of the Read diode device. It is made from silicon carbides due to higher breakdown fields.
The figure-1 depicts structure of IMPATT diode.
As shown it is combination of p+ - n - n+.
The junction between p+ and n is called avalanche region while
n+ region is called as drift space.
The IMPATT devices with two such drift regions are also available.
Refer difference between BARITT vs IMPATT vs TRAPATT diodes>>.
The IMPATT diode can be used for variety of applications as follows.
• Modulated output oscillator
• Microwave Generator
• Receiver LO
• Parametric Amplifier
• Intrusion alarm network
• FM telecommunication transmitters
• CW doppler radar transmitter
Benefits or advantages of IMPATT diode
Following are the benefits or advantages of IMPATT diode:
➨Operates from 3 to 100 GHz frequency range.
➨It has high power capabilities compare to other microwave diodes.
➨Its output is more reliable compare to other microwave diodes.
➨It acts as a narrow band device when used as amplifier.
➨It can be used as excellent microwave generators. It can produce carrier signal for microwave transmission system.
Drawbacks or disadvantages of IMPATT diode
Following are the disadvantages of IMPATT diode:
➨It has high noise figure due to avalanche process & higher operating current. The shot noise is generated in the device due to high operating current. Typically noise figure of IMPATT is about 30 dB.
➨It produces spurious noise (AM and FM) with higher levels compare to klystron and Gunn diodes.
➨The tuning range of IMPATT diode is not as good as Gunn diode.
➨It offers lower efficiency compare to TRAPATT diode.