Tunnel Diode

• Tunnel diode are utilised in microwave frequency range and ultra high frequency (UHF). They have their application in high frequency communication electronics .The schematic symbol and characteristic curve is given in fig.

• The operating curve is an outcome of very heavy doping utilized in manufacturing of the tunnel diode. In fact, the tunnel diode is doped almost 1000 times as heavily as standard pn junction diodes.
• In the forward operating area of the tunnel diode, we are concerned with the area between the peak voltage (Vpk) and the valley voltage (VV).
• At VF= Vpk forward current is known as peak current (IPK). As VF is increased to the VV and IF decreases to its least value known as Valley current (IV) .
• The term utilized to explain a device whose current and voltage are inversely proportional is negative resistance.
• Hence, the region of operation between Vpk and VV is known as negative resistance region.