What is the principal characteristic of a varactor diode?
Characteristics of Varactor Diode These diodes significantly generate less noise compared to other diodes. The cost of these diodes is available at lower and more reliable also. These diodes are very small in size and very lightweight. There is no use when it is operated in forwarding bias.
What is the significance of varactor diode?
The function of the varactor diode is to store charges, so it is always operated in reverse bias condition. When a forward bias voltage is applied, the electric current flows, as a result, the depletion region becomes negligible, which is undesirable.
What is construction of varactor diode?
A Varactor Diode consists of p-type and n-type semiconductor layers sandwiched together, with the n-type layer attached to a mesa (table-shaped) structure. A gold plated molybdenum stud is connected to n-type layer via the mesa structure and it acts as cathode terminal.
What is a varactor diode symbol of varactor diode?
Symbol of Varactor Diode The symbol of the varactor diode is similar to that of the PN-junction diode. The diode has two terminals namely anode and cathode. The one end of a symbol consists the diode, and their other end has two parallel lines that represent the conductive plates of the capacitor.
How does a varactor diode?
A varactor diode is a p-n-junction diode, in which internal capacitance can be altered as a result of the application of reverse bias voltage. The varactor diode works in the reverse bias condition. It is also known as Varicap diode or voltCap diode indicating varying capacitance.
Which of the following property exists in varactor diode?
The varactor diode is manufactured in such as way that it shows better transition capacitance property than the ordinary diodes.
When depletion region becomes widen in varactor diode plate separation?
Explanation: The width of the depletion region goes on increasing with increase in reverse bias voltage of the varactor diode. As the width of depletion region is an inverse function for capacitance, as the width increases, capacitance decreases.
What are the V-I characteristics of varactor diode?
V-I Characteristics of Varactor Diode. By applying a reverse voltage across varactor diode, the width Wd of the depletion layer increases. Therefore, the capacitance of the junction decreases. On the other hand, if we reduce the reverse voltage across the varactor diode, the width Wd of the depletion layer decreases.
Can a varactor diode be used in reverse bias?
Varactor diode can only be operated in reverse bias. It acts like variable capacitance in reverse bias operation. Varactor Diode is also known as Tuning Diode, Variable Reactance Diode, Varicap Diode or variable capacitance diode.
How is the capacitance of a varactor diode related to the depletion layer?
The junction capacitance of a p-n junction diode is inversely proportional to the width of the depletion layer. In other words, if the width of the depletion layer is less, then, the capacitance is more, and vice versa. So if we need to increase the capacitance of a varactor diode, the reverse bias voltage should be decreased.
How is a p-n junction diode a variable capacitor?
A P-N junction diode which acts as a variable capacitor by changing reverse bias is known as a Varactor Diode. Word Varactor is given to it due to its property of varying capacitance. Varactor diode can only be operated in reverse bias. It acts like variable capacitance in reverse bias operation.