Question 5.223: Name any two applications of tunnel diode?...

Tunnel diode is a type of semiconductor diode which is capable of very fast and in microwave frequency range. It was the quantum mechanical effect which is known as tunneling. It is ideal for fast oscillators and receivers for its negative slope characteristics. When the voltage is first applied current stars flowing through it. The current increases with the increase in voltage. Once the voltage rises high enough suddenly the current again starts increasing and tunnel diode stars behaving like a normal diode. Because of this unusual behavior, it can be used in several special applications started below:

1. Oscillator circuits

Tunnel diodes can be used as high-frequency oscillators as the transition between the high electrical conductivity is very rapid. They can be used to create oscillation as high as 5Gz. Even they are capable of creativity oscillation up to 100 GHz in an appropriate digital circuit.

2. Microwave circuits

Normal diode transistors do not perform well in microwave operation. So, for microwave generators and amplifiers tunnel diodes are used. In microwave waves and satellite communication equipment, they were used widely, but lately, their usage is decreasing rapidly, as transistors that operate in this frequency range are becoming available.