This section provides an overview for rf amplifiers as well as their applications and principles. Also, please take a look at the list of 45 rf amplifier manufacturers and their company rankings. Here are the top-ranked rf amplifier companies as of November, 2024: 1.Electronics & Innovation, Ltd., 2.NuWaves Engineering, 3.Industrial Test Equipment Co., Inc..
Table of Contents
The "RF" in RF Amplifier stands for "Radio Frequency" and refers to the high frequency used in mobile wireless communications such as radios and smartphones.
In general amplifiers, the input voltage or current is amplified and output, but in the case of RF amplifiers, instead of this function, DC bias is used to amplify high-frequency power signals by the gain of the amplifier relative to the input power. Therefore, the power for DC bias can be used for amplifying high-frequency power with relatively high efficiency without loss of DC bias power.
It should be noted that the electrical characteristics required for RF amplifiers, i.e., the type of amplifier, differ depending on whether they are used for receiving or transmitting circuits.
RF amplifiers are characterized by their ability to amplify and convert DC power to high-frequency power without loss of DC power, and are considered to be highly efficient RF Amplifiers. The type differs depending on whether it is used for receiving or transmitting circuits.
RF circuits for communication are divided into blocks for receiving and transmitting, and the type of RF amplifier generally differs depending on whether it is used for receiving or transmitting.
RF amplifiers used on the transmitting side are called Power Amplifiers (PA), which require high amplification. Because of the large amount of power handled, it is important to have low power consumption, i.e., high amplifier efficiency, in order to maintain reliability by suppressing heat generation and battery power consumption. Also, depending on the application, the amplifier itself must have sufficient linearity to prevent signal distortion.
On the other hand, RF amplifiers used for reception are called Low Noise Amplifiers (LNA). They are characterized by low noise (NF) generated by the amplifier itself to prevent the signal from being buried in the noise and to maintain communication quality by increasing the reception sensitivity during communication.
Si MOSFETs, SiGe bipolar transistors, HBTs and HEMTs using compound semiconductors such as GaAs and GaN crystals are used as semiconductor devices for RF amplifiers. It is important to select the optimum semiconductor device according to the maximum output power, gain, efficiency, linearity, and noise figure of the RF amplifier.
Depending on the RF frequency, the frequency response, called the cutoff frequency (fT), may not be sufficient to draw sufficient amplification. Therefore, the stand-alone frequency response determined from the structure of the semiconductor device is a very important factor in constructing an RF amplifier.
The amplifier characteristics are determined by applying the desired DC bias to the amplifier device and optimally setting the input and output load lines of the amplifier. In addition to the fundamental frequency impedance setting, the harmonic impedance setting is also important, and together with the bias, various operating classes (Class A, Class C, Class F, etc.) can be set.
RF Amplifier characteristics include 1 dB compression, gain, and noise figure. In the gain and power curves, 1dB compression is used as a measure of the maximum amount of power output with 1dB of gain suppressed due to amplifier saturation operation.
Since a large output power is required on the transmit side, it is customary to select an amplifier with a large 1 dB compression region and use it up to its upper limit. An RF amplifier can express its frequency response by its amplification, which is the power ratio between input and output, and its performance is judged by its being within a fixed range of frequency The higher the gain, the better.
Higher gain is desirable, but care must be taken as it is a trade-off between power consumption and noise. The noise figure expresses the degree to which the signal-to-noise ratio worsens. When selecting the RF amplifier for the receiving side, choose a small noise figure.
*Including some distributors, etc.
Sort by Features
Sort by Area
A.H. Systems, Inc., established in 1974 and headquartered in Camarillo, California, USA, is a manufacturer and supplier of antennas for compliance testing. The company's product range includes Antenna Kits, Biconical Antennas, Biological Antennas, Current Probes, and Dipole Antennas. These products satisfy many test standards, including CISPR, MIL-STD, FCC, IEC, and SAE. The company's services entail antenna calibration, antenna rental, and a discount warehouse. It is devoted to providing quality products and services to its customers. The company is ISO 9001:2015 certified and has a long history of customer satisfaction.
Broadcom Inc., established in 1961, and headquartered in San Jose, California, is a manufacturer and supplier of semiconductor and connectivity solutions. The company specializes in producing products, such as semiconductors, infrastructure software, networking products, storage products, wireless products in which their products cater to industries such as telecommunications, data centers, and consumer electronics. Their products are used for various applications, including wireless communication, networking equipment, data storage, and multimedia devices, providing components for advanced technologies in numerous industrial and commercial sectors.
Crane Co. is a diversified manufacturer of engineered industrial products that was established in 1855 and is headquartered in Chicago, Illinois, USA. The company produces a wide range of products, including sensing components and systems, landing systems, fluid management, electrical power solutions and microwave solutions. Its products, such as Crane Fluid Systems, Crane Control Systems, and Crane Valves, are used by a number of industries, as diverse as oil and gas, aerospace, and power generation industries. The company provides aftermarket services, including AOG (aircraft on ground), Repair Capabilities, RFQ, component maintenance, and modernizations and, upgrades.
Integra Technologies, founded in 1997, is a manufacturer and supplier of RF power devices located in El Segundo, California. The company specializes in providing radar signal amplification solutions, encompassing RF power transistors, RF power amplifier modules, and RF power pellets. These products are designed to handle high-power RF signals efficiently and are used in various applications, such as avionics, defense, instrumentation, and weather radar. Integra Technologies ensures continued support for legacy programs and offers customization options to meet specific design requirements.
Spectrum Control is based in Pennsylvania, USA, and is a manufacturer of microwave and radio frequency (RF) subsystems and components for the defense industry that was originally established in 1963 before its acquisition by API Technologies in 2011. The company produces conditioning and distribution products such as RF signal couplers, digital blocks such as RF signal modulators, and power distribution accessories such as inverters. It also offers EMI protection products and integrated microwave assemblies tailored to customer specifications. The company’s products are used in the defense and aerospace industries, with additional applications in military-grade secure systems.
QuinStar Technology, Inc., established in 1993, is an American manufacturer located in Torrance, California, specializing in millimeter-wave (MMW) and radio frequency (RF) technology and solutions. QuinStar offers a range of high-performance active and passive RF components. They also provide fully integrated and customized MMW assemblies and subsystems, including miniature transceivers, broadband receivers, antenna subsystems, and communication front ends. These products, assemblies, and subsystems are extensively used in the commercial, scientific, and defense sectors for digital and analog sensors, communication, and test applications. QuinStar is also involved in space programs, contributing to engineering development, design studies, and the production of flight hardware.
Qorvo, established in 2015, is a semiconductor manufacturer headquartered in Greensboro, North Carolina, USA, that specializes in providing RF (Radio Frequency) solutions. Their range of product offerings includes RF chips, modules, amplifiers, discrete transistors, and integrated circuits, designed to enable wireless communication, enhance defense systems, support automotive applications, facilitate aerospace operations, and enable connectivity in the Internet of Things (IoT) sector. Qorvo is certified with ISO 9001 for quality management and ISO 14001 for environmental management.
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.
Rohde and Shwarz, headquartered in Munich, Germany, is a technology business that creates, develops, and promotes innovative information and communication technology products for professionals. Customers all over the world rely on Rohde & Schwarz and its cutting-edge solutions in the test & measurement, secure communications, networks & cybersecurity, and broadcast & media areas. They were created in 1993 and have regional hubs in Asia and the United States.Rohde & Schwarz has invested heavily in emerging technologies such as artificial intelligence, the industrial internet of things (IIoT), 6G, cloud solutions, and quantum technology.
Founded in Irvine, CA in 1962, Skyworks Solutions, Inc. designs, develops, manufactures, and markets proprietary semiconductor products. Its product portfolio includes amplifiers, antenna tuners, attenuators, automotive tuners and digital radios, clocks and timings, circulators/isolators, DC/DC converters, demodulators, detectors, diodes, wireless analog system on chip products, directional couplers, diversity receive modules, filters, front-end modules, hybrids, LED drivers, low noise amplifiers, mixers, modulators, switches, synthesizers, timing devices, technical ceramics, voltage controlled oscillators/synthesizers, and voltage regulators. The company provides its products for the usage in aerospace, automotive, broadband, cellular infrastructure, connected home, entertainment and gaming, industrial, medical, military, smartphone, tablet, and wearable markets.
Fairview Microwave was established in 1992 in Lewisville, TX, and is a manufacturer of RF and microwave components for industrial automation, military defense, telecom-broadband, commercial electronics, and building automation industries. Its RF product catalog includes RF noise source generators, RF power dividers and tappers, RF coaxial surge protector lightning, RF connector dust caps, and RF power combiners. The company also designs bias tees, calibration kits, frequency synthesizers, impedance matching pads, and hybrid couplers. It provides cable phase matching, 3D CAD drawings, and RF cable design services.
Incorporated in 1965, Analog Devices, Inc. designs, manufactures, tests, and markets integrated circuits (ICs), software, and subsystems that leverage analog, mixed-signal, and digital signal processing technologies. The company provides data converter products, power management and reference products for power conversion, driver monitoring, sequencing, and energy management applications in the automotive, communications, industrial, and high-end consumer markets. In addition, the company provides digital signal processing and system products for high-speed numeric calculations. It serves clients in the industrial, automotive, consumer, instrumentation, aerospace, and communications markets.
NuWaves RF Solutions was established in 2000 and is headquartered in Middletown, Ohio, USA focusing on designing, developing, and supplying RF (Radio Frequency) products and engineering services. The company specializes in RF and microwave solutions and offers various RF products, including Power amplifiers, RF filters, Frequency converters, RF switches, and RF transmitters for enhanced RF communication and signal processing capabilities. Its customers include government agencies and defense contractors for enhanced communication systems, electronic warfare capabilities, and radar systems Original equipment manufacturers (OEMs), research institutions, and commercial enterprises also benefit from wireless connectivity, automation, and IoT applications.
Electronics & Innovation, Ltd. (E&I), founded in 2003 with headquarters in Rochester, New York, is a manufacturer of RF power amplifiers. Their product range includes broadband RF amplifiers, amplifier modules, phased array systems, impedance matching and variable transformers, and RF components, catering to diverse applications in medical, security & defense, test & measurement, aerospace, and communications. These products enable accurate signal analysis in research and development processes and are utilized in wireless communication systems for remote patient monitoring in the medical sector and support radar and communication systems in security & defense.
Comtech Xicom Technology has its headquarters in Silicon Valley, California, and has been a manufacturer of satellite communications (satcom) amplifiers since 1991. For commercial and military applications, they offer Airborne High-Power Amplifiers (HPAs), including Traveling Wave Tube Amplifiers (TWTAs), Klystron Power Amplifiers (KPAs), solid-state power amplifiers (SSPAs), and Block Upconverters (BUCs). These HPAs are useful for ground, air, and maritime communications links. The company has a wide network of distributors in the Asia Pacific region, covering Australia, Japan, South Korea, Middle East, and Europe.
Rochester Electronics, LLC is a manufacturer stocking distributor of end-of-life semiconductors and the broadest range of active semiconductors that is headquartered in Newburyport, Massachusetts, and was founded in 1981. The company caters to manufacturing services ranging from design, wafer processing, testing, reliability, and IP Archiving. These specifically include OCM, build-to-order products, process flows, and standard packaging creation. The company pivots on manufacturing and distributing semiconductors that are no longer produced by its original manufacturer.
AR RF/Microwave Instrumentation, founded in 1969 and located in Souderton, Pennsylvania, is a distributor and manufacturer of AR and RF/microwave instrumentation. The company’s diverse product range includes AR systems, amplifiers, antennas, conductivity test systems, and RF test accessories. These products are used in research and development, testing laboratories, manufacturing, telecommunications, and defense sectors. AR RF/Microwave Instrumentation's offerings facilitate accurate testing, validation, and analysis of RF and microwave components, systems, and devices, ensuring efficient performance in electronic systems and communication technologies. The company is also ISO 9001:2015 certified and ISO 17025:2017 accredited.
Mini-Circuits, founded in 1968 and headquartered in Brooklyn, New York, is a designer, manufacturer, and distributor of RF and microwave components and integrated assemblies. The company’s range of products includes adapters, amplifiers, attenuators, cables, and frequency multipliers. Mini-Circuits' products are used to provide essential components and solutions for RF and microwave communication, signal processing, and testing across industries such as telecommunications, aerospace, defense, research, and manufacturing. Their offerings enable efficient signal transmission and manipulation in diverse applications where RF and microwave technologies play a role. The company also holds ISO 9001, AS 9100, and ISO 14001 certifications.
Pasternack headquartered in Irvine, California, is part of the Infinite Electronics family of brands, established in 1972 by Murray Pasternack, as a supplier of RF and Microwave components. The company retails various types of products, including connectors, switches, cables, couplers, and filters. They have over 40,000 in-stock products and have partnered with 19 international distributors serving customers in over 35 countries. The company offers contract assembling, where they assemble custom Cables for same-day shipping. The company earned the ISO 9001 certification in 2015 and offers expert technical support and 24/7 customer service.
US Anodize, formally known as Industrial Metal Plating, is based in Pennsylvania, United States, and specialized in aluminum anodizing and chromate conversion since 1959. The company offers custom anodizing solutions including oxide coatings of up to 2.0 mils and permanent finishes in unique colors. Anodizing is an electrochemical finishing process that ensures durability and corrosion resistance. US Anodize also provides chromate conversion coatings meant to protect aluminum alloys from corrosion while retaining their electrical conductivity. They also offer laser engraving services for various materials such as plastic and leather.
RFMW has been a supplier and distributor of specialized radio frequency (RF) and microwave components since it was founded in 2003 and is based in California. They provide RF & Microwave and Power Component distribution that focuses on Technical and Supply Chain Solutions and these include Active Devices like Diodes, Transistors, Amplifiers, Control Components, and more along with Passive devices such as Filters, Inductors, Antennas and alike. They also have Power Management and Interconnect/T&M components which help them serve military, aerospace, test, measurement, medical, and commercial markets.
Founded in 2003, Aaronia AG is a German manufacturer based in Strickscheid, specializing in measuring, tracking, and monitoring technology. Initially focusing on spectrum analyzers, including the first portable handheld model introduced in 2008, the company expanded its product line to include antennas, preamplifiers, signal generators, shielding materials, and related accessories. In 2013, Aaronia developed AARTOS, a drone detection system, most recently used in the security infrastructure of the 2022 G20 Summit in Bali, Indonesia. With real-time analysis software, Aaronia offers customized integration of hardware components for diverse applications. The company also provides GPS logger software to collect data from the antennas.
Zurich Instruments AG, founded in Zurich, Switzerland, in 2008 is a manufacturer of test and measurement equipment. The company's product portfolio includes quantum computing control systems, lock-in amplifiers, arbitrary waveform generators, impedance analyzers, and phase-locked loops. Their products are used in markets such as Automotive and Transportation, Telecommunications, Industrial Automation, Healthcare and Medical Devices and Aerospace and Defense. The company also offers customer services that include support, custom research projects and customized services.
Renesas Electronics Corporation was established in 2002 and is headquartered in Tokyo, Japan. Renesas is a global research, design, and manufacturer of semiconductors used in industries spanning automotive, consumer electronics, the internet of things, power & energy, and industrial sectors. Renesas manufactures both analog and digital products. Analog products include amplifiers, audio & video devices, data converters, PLC, and switches & multiplexers. Digital products include microcontrollers, memory components, sensors, wireless connectivity products, and others. Renesas also offers design resources such as kits, development tools, partner programs, and design tools.
Silicon Radar, founded in Frankfurt (Oder), in 2006 is a manufacturer of standardized chip products and customer-specific solutions for radar market segments. The company's product portfolio includes receivers, transceivers and LNAs (Low Noise Amplifiers). The company serves markets including Automotive and Electric Vehicles, Renewable Energy and Energy Storage and Electronics and IT Infrastructure. The company also offers customer services that include technical support, quality control, custom research projects and customized services.
Tekbox Digital Solutions, founded in 2008 and located in Singapore, is a manufacturer of environmental monitoring products and test equipment. The company specifically fabricates multi-sensors remote terminal units, converters, sensor interfaces, antennas, and comb generators. It also produces coaxial adapter sets, self-powered active loads, high-pass filters, and anemometers. It applies electromagnetic compatibility pre compliance testing during the design phase that could reduce time to market and product development cost significantly. Its multi-sensors remote terminal units allow connecting up to 2 SDI-12 sensors, 2 analog sensors, and one pulse sensor.
TEKTRONIX, INC., founded in 1946, is a manufacturer of measurement solutions used in 3D sensing, EMI/ EMC testing, high-speed serial communication, material science engineering, and Wireless & RF testing. The products include oscilloscopes & probes, signal generators, margin testers, multimeters, and analyzers. The company's products are used in advanced research, aerospace & defense, automotive, power semiconductor, and medical industries. The Bracknell Berkshire company offers calibration, repair, asset management, package assembling, and testing services following NEMA, HAlT & HASS, environmental, and shock-vibration testing.
Marki Microwave Inc. is an ISO 9001:2015-certified broadband and high-frequency microwave product manufacturer established in 1991 in Morgan Hill, California, USA. The company offers filters for passing or rejecting signals based on frequency, amplifiers for increasing the amplitude or power of selected signals, and mixers for combining two or more signals at different frequencies. It also offers power dividers, couplers, and baluns for converting balanced signals. The company’s products are used in the telecom, aerospace, and defense sectors.
Acme Chip Technology Co. Ltd., founded in 2008 and based in Shenzhen, China, is a distributor of electronic components that is ISO 9001 certified. Its products include sensors, power supplies, and optical inspection equipment sourced from several manufacturers, including Advanced Linear Devices Inc., Central Semiconductor Corp., and Fluke. The company also offers a large stock of electronic components, including obsolete components and old code chips that are always available for immediate shipment.
Infineon Technologies AG (Infineon) is headquartered in Neubiberg, Germany. Infineon designs, develops, manufactures, and markets semiconductors and related system solutions worldwide. Infineon’s automotive segment produces microcontrollers, discrete power semiconductors, IGBT modules, industrial microcontrollers, power and radar sensor ICs, SiC diodes, MOSFETs voltage regulators, comfort electronics, infotainment, powertrain, and security products. Industrial Power Control segment provides bare dies, discrete IGBTs, and driver ICs among other components. Power & Sensor Systems segment offers gas and pressure sensors, MEMS microphone chips, control ICs, and GaN power switches among others.
Anokiwave, founded in Billerica, Massachusetts, in 1999 is a manufacturer of commercial mmW Active Antennas and 5G products. The company's product portfolio includes 5G Gen-4 Products, SATCOM, RADAR, Space, and NextG applications. The company serves industries such as Oil and Gas, Aerospace and Defense, Automotive and Transportation, Construction, and Power Generation. The company architectures low loss antenna designs for further energy savings that maximizes consumption factor (EIRP/DC power) to minimize environmental footprints.
CML Microcircuits (UK) Ltd., established in 1968 and headquartered in Maldon, Essex, United Kingdom, is a mixed-signal, RF, and microwave semiconductor developer and manufacturer. The company's products include modular radio frequency (RF) blocks, digital and analog data controllers, and digital voice encoders supporting coding, transcoding, and decoding. It also produces a series of telecommunication-application modems, mmWave MMICs, and baseband processors. These products are used in satellite communications, consumer wireless products, and maritime communications.
Texas Instruments Incorporated was founded in 1930 and is headquartered in Dallas, Texas. Texas Instruments is a producer of high tech equipment for industrial, automotive, personal electronics, communications equipment industries. Texas Instruments designs, manufactures, and sells semiconductors to electronics designers and manufacturers in the United States and internationally. Texas Instruments operates in two segments: analog and embedded processing. The Analog segment offers power products, including battery-management solutions, DC/DC switching regulators, power switches, linear regulators, voltage references, and lighting products. The Embedded Processing segment offers microcontrollers that are used in fields such as electronic equipment and digital signal processors for mathematical computations.
Arrow Electronics, Inc. is a manufacturer and supplier of electronic components and enterprise software that was established in 1935 in New York City, New York, USA. The company primarily produces electronic components including interconnect cable assemblies, semiconductors, and fiber optics. It also offers enterprise computing software such as security suites, servers, and cloud hosts. The company is ISO 9001, ISO 14001, and ISO 45001-certified, and provides custom design as well as engineering services for its clients with unique projects.
Value Tronics International Inc., founded in 1992 and based in Elgin, Illinois, is a distributor of a wide range of equipment, such as signal generators, power supplies, and spectrum analyzers. The company stocks over 8,000 products, including used and new equipment from over 300 manufacturers like Berkeley Varitronics, Compression Techniques, and Delta Elektronika. It also buys obsolete and unused testing and lab equipment, which includes meters, oscilloscopes, and data loggers. The company provides financing options that allow customers to pay for purchases later. It also has a loyalty program where customers earn a 2% credit after a purchase.
Richardson RFPD, based in Geneva, Illinois, is an electronic component distributor that became a subsidiary of Arrow Electronics in 2011. The company stocks products such as antennas, power supplies, and ICs, and its engineering team brings together over 600 years of combined design experience in IoT product development, wireless, and RF, making it competent from conception to production. The company is ISO 9001 certified and has three international distribution hubs in Asia, Europe, and North America. It sells products from several brands, including Advanced Thermal Solutions, Empower RF Systems Inc., and Carlisle Interconnect Technologies.
PHOTONIS, a well-reputed French company founded in 1937, specializes in manufacturing electro-optic components and detectors. They offer a wide range of products, including photomultiplier tubes, image intensifiers, and microchannel plates. PHOTONIS serves various industries, such as scientific research, defence, medical, and industrial applications. Their products are used in applications like night view, mass spectral analysis, and space exploration. PHOTONIS is present internationally with offices and distributors in different countries. Devoted to excellence and environmental responsibility with various certifications, ensuring reliability and safety for customers.
Emhiser Micro-Tech was founded in 1992 and is headquartered in Nevada, United States, as a supplier of ceramic resonator VCOs designed for narrow-band applications with very low phase noise. EMT persistently challenges the conventional practices linked to commercial VCO producers by creating, manufacturing, and promoting a product that ensures comprehensive quality, dependability, and customer contentment. The organization acknowledges the challenges inherent in the customer experience and is engrossed in delivering customer service, fostering loyalty, and offering a dependable product.
Ranking as of November 2024
Derivation MethodRank | Company | Click Share |
---|---|---|
1 | Electronics & Innovation, Ltd. |
6.0%
|
2 | NuWaves Engineering |
5.6%
|
3 | Industrial Test Equipment Co., Inc. |
4.1%
|
4 | QuinStar Technology, Inc. |
4.0%
|
5 | Analog Devices, Inc. |
3.7%
|
6 | Integra Technologies |
3.3%
|
7 | Broadcom |
3.3%
|
8 | A.H. Systems, inc. |
3.1%
|
9 | US Anodize |
3.1%
|
10 | CRANE CO |
3.1%
|
Derivation Method
The ranking is calculated based on the click share within the rf amplifier page as of November 2024. 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 | 23 | 82.1% |
Germany | 2 | 7.1% |
Switzerland | 1 | 3.6% |
Japan | 1 | 3.6% |
Singapore | 1 | 3.6% |
29 products are listed.
Wave Crest
30+ people viewing
■ Characteristics ・ Prepare a 10kHz-6GHz 70 standard RF power amplifier ・ It also supports custom power amplifier specifications of 6GHz-40GHz ・...
Wave Crest
30+ people viewing
■ Characteristics ・ Prepare a 10kHz-6GHz 70 standard RF power amplifier ・ It also supports custom power amplifier specifications of 6GHz-40GHz ・...
Wave Crest
30+ people viewing
■ Characteristics ・ Prepare a 10kHz-6GHz 70 standard RF power amplifier ・ It also supports custom power amplifier specifications of 6GHz-40GHz ・...
Wave Crest
30+ people viewing
■ Characteristics ・ Prepare a 10kHz-6GHz 70 standard RF power amplifier ・ It also supports custom power amplifier specifications of 6GHz-40GHz ・...
Wave Crest
70+ people viewing
■ Characteristics ・ Prepare a 10kHz-6GHz 70 standard RF power amplifier ・ It also supports custom power amplifier specifications of 6GHz-40GHz ・...