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This section provides an overview for varactor diodes as well as their applications and principles. Also, please take a look at the list of 5 varactor diode manufacturers and their company rankings. Here are the top-ranked varactor diode companies as of January, 2025: 1.MACOM, 2.Skyworks Solutions, Inc., 3.BYJU'S.
Table of Contents
A varactor diode is a diode whose capacitance can be varied by applying a reverse voltage.
They are also called variable capacitance diodes or varicaps. Generally, when a reverse voltage is applied to the PN junction of a diode, the depletion layer, which is the area without carriers such as electrons and holes, behaves like a capacitor.
A varactor diode actively utilizes the property that the capacitance, which acts as a capacitor, varies depending on the magnitude of the applied voltage.
Varactor diodes are used in electronic components, such as electronic tuning circuits and voltage controlled oscillators (VCOs). Electronic tuning circuits and voltage controlled oscillators (VCOs) are used in devices that receive radio waves, such as radios, televisions, telecommunications equipment, and mobile communication devices, such as smartphones.
In order for those devices to receive signals at specific frequencies, the capacitance of the capacitors in the receiver and the impedance value of the coil must be adjusted. For this purpose, varactor diodes are used, whose capacitance can be controlled by voltage.
The principle of varactor diode is to utilize as capacitance the carrier-free depletion layer that is created when a reverse voltage is applied to the PN junction of the diode. Also, to actively use the characteristic that the value of the capacitance depends on the reverse voltage value. In an ordinary diode, forward current flows when a bias voltage is applied in the forward direction, and no current flows when a bias voltage is applied in the reverse direction.
When the voltage is applied in the opposite direction, holes move from the P-type semiconductor part to the electrode and electrons move from the N-type semiconductor part to the electrode, forming a depletion layer with no carriers in the PN junction part. Since there is no charge in the depletion layer and charge is generated on both sides of the depletion layer, the diode behaves like a capacitor.
If the absolute value of the applied voltage in the reverse direction is large, the thickness of the depletion layer increases by that amount, resulting in a smaller equivalent capacitance. A varactor diode is a diode whose capacitance changes by varying the value of the applied reverse voltage. This capacitance change characteristic is effectively utilized.
Since the capacitance value of a varactor diode can be varied by the bias applied voltage, it is possible to form an LC resonance circuit with an inductor and adjust its resonance frequency.
Using an LC resonant circuit that can be varied by the voltage value, a voltage-controlled oscillator (VCO), for example, incorporates a resonant circuit in a Colpitts oscillator.
A voltage-controlled oscillator (VCO) is a part of the PLL (Phased Lock Loop), which is a frequency adjustment circuit for mobile communications. It is a very important circuit for cellular communication applications between base stations and mobile terminals. As a tuning circuit, the LC resonant circuit is also used in FM modulation applications, such as radio.
The word "varactor" in varactor diode stands for "variable reactor," meaning a variable reactance, and in the case of varactor diodes, it specifically refers to a capacitive variable reactance. Varicap, on the other hand, is an abbreviation for "variable capacitor" and literally means variable capacitance.
While both varactor and varicap are abbreviations for variable capacitance, it should be noted that the diode bias on the reverse side, where capacitance can be varied, also has a breakdown voltage (breakdown voltage). Check the electrical specifications of the varactor diode you plan to use carefully, and use a voltage within the usable range of the reverse side.
The breakdown voltage (breakdown voltage) is also called the Zener voltage, and diodes that actively use this region are also called Zener diodes. Zener diodes are often used in protection circuits to prevent overvoltages from being applied to the circuitry of the device, or in circuits for constant voltage generation.
*Including some distributors, etc.
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Microchip Technology Incorporated was incorporated in 1989 and is headquartered in Chandler, Arizona. The company is a developer and manufacturer of control solutions for global markets including the automotive, industrial, communications, human-machine interface, and connectivity industries. The company’s products include microcontrollers, field-programmable gate array products, MOSFET and radio frequency products, and both wired and wireless communications products. The company’s services include wafer foundry and assembly services, test subcontracting manufacturing services, development tools for enabling system designers to program microcontrollers and processors, and timing system products.
OMMIC, founded in Lowell, MA, in 1950 is a manufacturer of semiconductor products for Data Center, Telecommunication and Industrial and Defense applications. The company's product portfolio includes Optical Networking Solutions, Lightwave Components, Diodes, MMICs, and SDI Products. The company serves markets including Automotive and Electric Vehicles, Renewable Energy and Energy Storage and Electronics and IT Infrastructure. They have design centers and sales offices throughout North America, Europe and Asia and have ISO9001 international quality standard and ISO14001 environmental management standard.
Skyworks Solutions, Inc. is based in Irvine, California, and is a wireless communication products manufacturer that was established in 2002 following the merger of Conexant Systems’ wireless communications division and Alpha Industries. The company’s products include switches, isolators, amplifiers, and modulators for applications such as vehicle-to-everything (V2X) communication or smart metering, as well as cellular and 5G connectivity platforms for wearables, smartphones, and tablets. It also offers design support, testing, and quality assurance services for customer projects. The company’s products are primarily used in wireless infrastructure, mobile communication, and consumer as well as IoT electronics.
Tutorials Point (India) Private Limited, founded in 2014, is an Indian manufacturer based in Madhapur, Telangana, specializing in developing an online library and a digital content marketplace. The company’s platform, Tutorials Point, offers videos, e-books, and other learning materials within the Text Library Content on technical and non-technical subjects, including academic subjects, big data and analytics, computer science and programming, machine learning, and website development. The platform features over 5,000 premium courses, 1,200 expert tutors, and 30 million online students. Additionally, the company offers team training solutions and develops the Digital Content Marketplace, allowing users to sell video courses and e-books.
Byju's (stylised as BYJU'S), founded in 2011 and a subsidiary of Think and Learn Pvt. Ltd., is an Indian educational technology company headquartered in Bangalore, Karnataka, specializing in educational websites and applications. The company has developed BYJU'S - The Learning App, BYJU'S Disney Early Learn App, and BYJU'S Parent Connect App, offering self-paced learning through digital animation videos and related learning materials. Notably, the company launched BYJU’S WIZ, a suite of artificial intelligence (AI) models for hyper-personalized learning. Byju's has expanded its reach through acquisitions of educational companies like Great Learning Pvt. Ltd., Epic! Creations, Inc., TutorVista, and Edurite from Pearson PLC.
Ranking as of January 2025
Derivation Method| Rank | Company | Click Share |
|---|---|---|
| 1 | MACOM |
34.5%
|
| 2 | Skyworks Solutions, Inc. |
31.0%
|
| 3 | BYJU'S |
20.7%
|
| 4 | Tutorials Point |
13.8%
|
Derivation Method
The ranking is calculated based on the click share within the varactor diode page as of January 2025. Click share is defined as the total number of clicks for all companies during the period divided by the number of clicks for each company.Number of Employees
Newly Established Company
Company with a History
*Including some distributors, etc.
*Including some distributors, etc.
| Country | Number of Companies | Share (%) |
|---|---|---|
|
United States of America
|
3 | 75.0% |
|
India
|
1 | 25.0% |
8 products found
8 products
Keisei Co., Ltd.
70+ people viewing
Last viewed: 6 hours ago
Standard Response
■Features ・Application: VHF/UHF VCO ・Number of circuits: 1 ・RoHS Compatible Product (s) Compatible products available
Towa Electronics Co., Ltd.
50+ people viewing
Last viewed: 6 hours ago
Standard Response
5.0 Company Review
This is a diode whose capacitance value is variable depending on the value of reverse bias voltage. Mainly used in high frequency matching circuits...
Towa Electronics Co., Ltd.
70+ people viewing
Last viewed: 48 minutes ago
Standard Response
5.0 Company Review
This is a diode whose capacitance value is variable depending on the value of reverse bias voltage. Mainly used in high frequency matching circuits...
Isahaya Electronics Co., Ltd.
50+ people viewing
Last viewed: 13 hours ago
Very Fast Response
5.0 Company Review
The MC2837 is a small external resin-sealed silicon epitaxial double diode designed and manufactured for general switching applications. Since the...
Isahaya Electronics Co., Ltd.
50+ people viewing
Last viewed: 13 hours ago
Very Fast Response
5.0 Company Review
The MC2837 is a small external resin-sealed silicon epitaxial double diode designed and manufactured for general switching applications. Since th...
