It always works in reverse bias condition and is a voltage-dependent semiconductor device. When reverse-biased, they have a capacitance that varies with an applied voltage. A varactor diode, more commonly referred to as a varicap, is an electronic semiconductor device very closely related to a standard diode but with certain capabilities similar to a capacitor. 2. Varactor Diode is a reverse biased p-n junction diode, whose capacitance can be varied electrically. The capacitance of the Varactor Diode depends upon the voltage applied across its ends that is by increasing the voltage across the diode the capacitance decreases. Varies with the change in voltage applied to its terminals. Varactor diode is special type of PN junction diode, in which PN junction capacitance is controlled using reverse bias voltage. The depletion layer of a diode constructed in this manner varies in width in proportion to the voltage applied to it. Applications of … Varactor Diodes, also known as "variable reactance diodes ", are made using the characteristic that the junction capacitance varies with the applied voltage when the PN junction is reverse biased. Difference Between Half Wave and Full Wave Rectifier, Difference between Half Adder and Full Adder, Difference between Centre Tapped and Bridge Rectifier, Intelligent Electronic Devices (IED) in SCADA. The Varactor diodes belong to the family of semiconductor devices. The varactor diode is one type of PN junction diode whose internal capacitance changes with the applied reverse bias voltage. The P-N Junction diode creates capacitor effect. Once this force is strong enough to bridge the depletion layer, it will easily travel across the positively charged anode of the diode, and the diode will conduct electricity. It is also known as Varicap diode (Variable Capacitance). Abrupt varactor diodes are the more commonly used form of varactor. A varactor is a diode whose junction capacitance can be altered with an applied reverse voltage. These are special purpose diodes, also called a varicap diodes or tuning diodes or variable capacitance diodes, designed to work always in reverse bias state. If a negative voltage is applied to the anode lead of a diode, the potential of the negative voltage combines with the potential of the negative cathode. Varactor Diode is a P-N junction diode and is also known by different names such as varicap diode, varactor diode, tuning diode variable capacitor under different reverse bias voltage in its terminals. * Word Varactor is given to it due to its property of varying capacitance. Varactor Diode Basics As the purpose of this diode is to vary the value of capacitance hence the other name for this diode is a volt cap or varicap. A capacitor is an electronic component that stores electrical energy or electric charge in the form of an electric field. What is a Varactor Diode? This type of diode is used to store charges. It is meant for high frequency applications . Most diodes are designed to pass as quickly as possible through the area when current still flows and a capacitive electric field exists. All diodes are constructed of two pieces of different materials fused together with a lead attached to each end. The Varactor diode work always in reverse biased and it is voltage dependent semiconductor device.The term Varactor derived from variable capacitance and the diode behave like a variable capacitor under reverse biased condition. Varactor or varicap diodes are used mainly in radio frequency or RF circuits to provide voltage controlled variable capacitance. A varactor diode, more commonly referred to as a varicap, is an electronic semiconductor device very closely related to a standard diode but with certain capabilities similar to a capacitor. Symbol of Varactor Diode: Symbol of Varactor Diode What is a capacitor? Therefore the basic material used to manufacture diode is Gallium Arsenide or Germanium . “The term varactor is the shortened form of a variable reactor, which refers to the voltage-variable capacitance of a reverse-biased p-n junction.” Varactor diode is also known as a variable diode, vericap diode, tuning diode, variable reactance diode, or variable capacitance diode. For this reason, a varactor is also called a variable capacitance diode (also it's called a varicap). Varactor diodes, however, are not always used simply to reduce cost and ease manufacturing processes. Varactor diodes, also called varicaps, are semiconductor devices that behave like variable capacitors. Varactor diode can only be operated in reverse bias. We know that holes are majority charge carriers in P-type semiconductor material and electrons are majority charge carriers in N-type semiconductor material. These types of diodes work on the principle that all diodes exhibit some capacitance. As a result these diodes are also referred to as varicaps, tuning diodes, voltage variable capacitor diodes, parametric diodes and variable capacitor diodes. What is Varactor diode, How Varactor diode works, Electronic Devices & Circuits, Engineer Concepts. At first this field only slows the flow of electrical current passing through the diode, but as the voltage increases and the field builds in strength, the field will eventually become strong enough to block electrical current from passing through the diode completely. varactor diode is a diode in which the junction capacitance can be changed by varying the reverse bias applied to the diode. The capacitance is controlled by applied voltage. Varactor or Tuning Diodes. Varactor diode is also a semiconductor microwave solid-state device, it is frequently used in applications where variable capacitance is desired which can be achieved by controlling voltage. Varactor Diode Definition: The diode whose internal capacitance varies with the variation of the reverse voltage such type of diode is known as the Varactor diode. It is well known that the operation of the p-n junction depends on the bias applied which can be either forward or reverse in characteristic. The varactor diode always works in reverse bias, and it … There are two plates in the capacitor between which there is a dielectric materials. A varactor diode, however, is designed to operate within this zone. The difference between a varactor and a standard diode is that a standard diode is designed to minimize the device’s capacitance while a varactor diode is designed to use and exploit capacitance. Varactors are widely applied as electronic tuning devices in microwave systems. It has taken special care during manufacturing so that in comparison to the normal diodes it is known well for transition capacitance. Before going to varactor diode, let’s first take a look at the capacitor. Unlike a standard diode, the charged material in a varactor is added in a gradient pattern, which varies the strength of the charge across the width of the cathode and anode. The functionality of this diode is dependent on the voltage. As a result, the diode can act as a variable capacitor with the capacitive field, decreasing as more voltage is applied and increasing as less voltage is applied. When the diode is reverse biased, charges in the P and N semiconductors are drawn away from the PN junction interface and hence forms the high resistance depletion zone. Privacy. Wikibuy Review: A Free Tool That Saves You Time and Money, 15 Creative Ways to Save Money That Actually Work. When the same voltage is applied to the cathode lead of a diode, the depletion layer widens from both sides of the anode, with the positive anode sandwiched between the two negative forces creating a capacitive electric field inside the diode. ..... Our Mantra: Information is Opportunity. One material is negatively charged, called the cathode, and the other is positively charged, called the anode. Varactor Diode is a reverse biased p-n junction diode, whose capacitance can be varied electrically. Word Varactor is given to it due to its property of varying capacitance. Varactor diode is a p-n junction diode whose capacitance is varied by varying the reverse voltage. They are most often used in devices that require electronic tuning, such as radios. The varactor diode can be used in place of a more expensive and difficult to install device such as a variable capacitor. In a normal diode, this charged material is added as uniformly as possible across the widths of the cathode and anode to allow the diode to change states as quickly and at as low a voltage as possible. The word varicap is originated from the combination of word variable and capacitor. A Varactor Diode is a PN junction diode that is especially operated in reverse biased mode. As a result these diodes are also referred to as varicaps, tuning diodes, voltage variable capacitor diodes, parametric diodes and variable capacitor diodes. Varactor Diode Varactor diode is a type of diode whose internal capacitance varies with respect to the reverse voltage. In general, electronic circuits can be built with a various electrical and electronic components like resistors, capacitors, diodes, transistors, integrated circuits, transformers, Thyristors, etc. Indeed the zener diode BZX79C12 quoted above has, according to the data book, a capacitance of 65-85 pF at 0V and measured at 1 Mhz. A varactor diode is considered as a special type of diode that is widely used in the electronics industry and is used in various electronics applications. A varactor diode, also called varicap, VVC (voltage-variable capacitance, or tuning diode, is a type of semiconductor diode which features a variable voltage-dependent capacitance on its p-n junction when the device is reversed biased. It is combination of variable capacitor and diode . What is Varactor Diode : Varactor diode also known as the varicap or tuning is the two terminal passive electronic component which has a variable capacitance. What is Varactor Diode? A diode in this state is said to have a forward bias. It works on reverse biased mode. Creating the two different charges in the diode is accomplished by adding a negatively or positively charged material to the matrix of the diode. A varactor (which is a shortened form of variable reactor) is simply a pn-junction diode that has been engineered to maximize the value and range of junction capacitance with the goal of applying the device as a voltage controlled capacitor in various tuned circuits such as filters and oscillators. In electronics, a varicap diode, varactor diode, variable capacitance diode, variable reactance diode or tuning diode is a type of diode designed to exploit the voltage … Varactor diode is known by several names as Varicap, Voltcap, Voltage variable capacitance, or Tunning diode. As the abruptness of the junction is governed by the doping concentration and also the profile, this is controlled during the manufacture. Definition: Varactor diode is the one which works on the principle of variation in capacitance by changing the width of the depletion region of P-N junction. When a diode is first created, these two materials exchange electrons where they meet, creating an area within the diode called the depletion layer, which has no favored charge. Let us discuss about the diode which is a two terminal electrical device. Varactors are often used in applications such as television or radio tuners where their abilities allow them to lock onto a channel or station’s frequency very quickly. When the diode is forward biased, current will flow through the diode. 1. Abrupt varactor diodes. A varactor's capacitance varies as the applied reverse voltage to it changes. In other words, it is a special type of semiconductor diode. Varactor diodes find common use in parametric electronics, such as parametric amplifiers and other tuning circuits that can be varied by a change in voltage. There is a neutral space charge region (Junction) between these two which do not have any majority carriers. It is used for storing the charge. Definition: A P-N junction diode which acts as a variable capacitor by changing reverse bias is known as a Varactor Diode. a p-n junction diode which acts as a variable capacitor under varying reverse bias voltage across its terminals It acts like … These electronic componenta can be used in a whole variety of ways where a capacitance level needs to be controlled by a voltage. Your email address will not be published. It is a device whose capacitance changes with the variation in the applied reverse bias potential.It is also known as varicap or voltcap. A diode in this state is said to have a reverse bias. For AM Radio band applications a specific diode has been devised. In this video, what is varactor diode, it's working, the applications and some important specifications are explained. 3. What is Varactor Diode?It is type of Diode whose internal capacitance varies with the variation of reverse voltage. 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