Tunnel diodes can be used in
microwave applications. Quantum tunneling theory is used to explain the
tunneling phenomenon that take place in tunnel diodes. Tunneling phenomenon is actually a majority
carrier effect. Some of the advantages of tunnel diodes are low cost, less
weight, high speed, low noise, high peak current to valley current ratio and
low power operations. These parameters make tunnel diodes ideal candidate in
applications like microwave amplification and microwave oscillation. The tunnel
diode is a p-n junction semiconductor diode with negative resistance. Tunnel
effect is responsible for this negative resistance. Heavy doping is employed
during the construction of tunnel diodes. In tunnel diodes, Fermi level lie
inside the valence band in p-region and inside the conduction band in n-region.
While using for amplifier applications, tunnel diodes are connected either in
parallel or in series with a resistive load. Another common practice is
connecting tunnel diode to a microwave circulator.
No comments:
Post a Comment