Amplifiers - RF / Operational / Log Video
(aka Analog | Opamp | Logarithmic | SDLNA | EDLVA)
Manufacturers & Services

Amplifiers cover a very broad range of types (Class A, B, C, D, AB, logarithmic, etc.), form factors, connectorized or non-connectorized, discrete or fully biased and impedance matched, low or high power, low or high frequency, low or high voltage supplied, narrow or wide bandwidth. Fortunately, within this page you are practically guaranteed to find a manufacturer that already makes or will custom design a solution for you. Please consider contacting RF Cafe advertisers first.

| Discretes | Packaged & MMIC | Tube |

Aeroflex | www.973-887-5700 | Whippany, NJ
Attenuators, phase shifters, digital time delay units, LNA's, switches, modulators, dividers combiners & couplers, ferrites, levelers, duplexers, amplifiers, resistors, terminations.

Aeroflex | Metelics | www.408-737-8181 | Sunnyvale, CA
InGaP HBT amplifiers, Schottky PIN tunnel, varactor, step recovery diodes (SRD), sampling phase detectors, surface mount products, MIS capacitors.

AetherComm | www.760-598-4340 | San Marcos, CA
High power RF amplifiers (DC-40 GHz), low noise RF amplifiers (DC-40 GHz), medium power amplifiers (DC-40 GHz), receivers & transmitters (DC-40 GHz).

Agile Microwave Technology | 516-931-1760 | Hicksville, NY
RF amplifiers, limiters, switches, and multipliers. Our goal is to cut product cost by more than 50% by keeping our overhead low, by staying small and focusing on innovative designs which are inspired by the commercial wireless market. Our goal is to provide same or better performance, size and quality at a much lower cost through better engineering and outsourcing to U.S. based contract manufacturers.

AKON | 408-432-8039 | San Jose, CA
Microwave amplifiers 0.5 to 20.0 GHz, power dividers and gain (slope) equalizers 1.0 to 18.0 GHz, converter assemblies 2.0-20.0 GHz, filter banks and switch filter banks 2.0-18.0 GHz, discriminators.

Alliance Test Equipment | 508-671-9970 | Dudley, MA
Products from many manufacturers available at prices discounted up to 80% off manufacturer list price. We specialize in Agilent / HP / Keysight, Tektronix, Anritsu, Fluke and Rhode & Schwartz and others. We are a global organization and have the ability to source hard to find equipment through our network of suppliers.

Ampelon | +31 24 3552666 | The Netherlands
Discrete transistor amplifiers for mobile broadband infrastructure, radio & TV broadcasting, CO2 lasers & plasma, MRI, particle accelerators, radar & air-traffic control, non-cellular communications, RF cooking & defrosting, RF heating and plasma lighting.

Amplifier Technology Ltd | +44 (0) 8700 869 941 | Bristol, England
Designs and manufactures leading edge RF power amplifiers primarily for the defence and aerospace sectors.

ar rf/microwave instrumentation (formerly Amplifier Research) | 800-933-8181 | Souderton, PA
RF power amplifiers, solid state microwave amplifiers, TWT amplifiers, antennas, transient generators, EMC test systems and software, field probes and monitors, test accessories, and RF test system controllers.

AmpliTech | 631-521-7831 | Holbrook, NY
Designs, develops, and manufactures custom and standard state-of-the-art low noise amplifiers (LNAs) , medium power amplifiers, and amplifier-related sub-assemblies for commercial, SATCOM, space, and military markets. These designs cover the frequency range from 50 kHz to 40 GHz.

Anadigics | 908-668-5000 | Warren, NJ
Base station PAs, switches, handset PAs, gain block amplifiers, upconverters, downconverters, line amplifiers, drop amplifiers for cable systems, and transimpedance amplifiers for fiber optic applications, Cascade Calculator.

Analog Devices | 800-262-5643 | Norwood, MA
Op amps, switches, A/D, D/A, S&H, AD8347 direct conversion RFIC (800 MHz to 2.7 GHz), ADIsimPLL synthesizer circuit simulation software.

AR Worldwide (ARKalmus) | 425-485-9000 | Bothell, WA
300 kHz to 65 MHz modules for NMR, 10 MHz to 670 MHz for military, communications and EW, 20 to 1000 MHz amplifiers and amplifier modules for high energy physics, 900 MHz to 3 GHz; single frequency amplifiers for high energy physics. Power available in 50, 100, 250, 500, and 1000 W increments.

Axiom Test Equipment | 1-760-806-6600 | Vista, CA
Whether you need to rent, buy, sell, repair, sell or trade test equipment, we are committed to providing superior customer service and high quality electronic test equipment. In-house repair lab. For anyone seeking to offload surplus or obsolete equipment, we offer a trade-in program or we can buy the equipment from you.

Broadcast Concepts | 305-887-8400 | Medley, FL
Design, develop, test and manufacture RF amplifier products for FM, TV and Military applications. The business operates from a commercial manufacturing facility in Miami Florida.

Burr-Brown (now Texas Instruments)
IC solutions - Op amps, switches, A/D, D/A, S&H.

Celwave (now RFS) | 877-737 9675 | Meriden, CT
Base station antennas, microwave antennas, filters and combiners, repeaters, transmission line systems, waveguides, amplifiers, air and foam dielectric coaxial cables, factory-made jumper assemblies, connectors and a large variety of installation accessories.

Ciao Wireless | 805-389-3224 | Camarillo, CA
Amplifiers for multi-octave, octave & ½-octave, broadband, LNAs, and RF limiting. Replacement amplifiers for anything previously or currently made by JCA Technology, Cougar (connectorized versions), Avantek, WJ, CTT, Celeritek, Amplica, among others. Also manufacture radial combiners and space qualified filters. Environmental screening services available.

Comtech PST | 631-777-8900 | Melville, NY
RF & microwave amplifiers, control devices, limiters, switches.

CTT | 408-541-0596 | Sunnyvale, CA
GaAs FET, low-noise & power amplifiers 100MHz thru 50GHz, 0.5-40 GHz subassemblies.

Custom MMIC | 978-467-4290 | Westford, MA
Fabless RF and microwave MMIC designer trusted by government and defense industry OEMs with their biggest microwave circuit challenges to solve various size, weight, performance, and cost (SWaP-C) challenges throughout the microwave signal chain. We also have a line of off-the-shelf MMICs including amplifiers, mixers, attenuators, phase shifters, and switches. Over 25 years of combined experience in designing state-of-the-art MMIC chips for millimeter wave, point-to-point radio, VSAT, WLAN, and cellular systems as well as general microwave applications.

Daico Industries | 310-507-3242 | Carson, CA
Attenuators & amplifiers, programmable, DC to 18 GHz, up to 500 W CW, IP2 > +100 dBm, IP3 > +50 dBm, matched sets, phased matched, & amplitude matched, diode, GaAs, connectorized, through-hole, surface mount, commercial, military & space.

Delta Microwave | 805-240-1044 | Oxnard, CA
Filters, diplexers, multiplexers, filter/amplifiers, variable attenuators, integrated assemblies, power combiners, waveguides. Product frequencies from 1 kHz to 50 GHz with RF power handling up to 25 kW.

DEV Systemtechnik | +49 6031 6975 100 | Cologne, Germany
RF transmission and switching equipment including distributing and combining matrices, redundancy switching systems, RF-over-fiber and routing products, multiplexers, distribution amplifiers, splitters, and combiners, broadband active and passive products.

Elisra | + 972-3- 6175 111 | Israel
Designs, develops, manufactures, integrates and supports advanced system solutions for air, sea and land deployment.

Empower RF Systems | 310-412-8100 | Inglewood, CA
Founded in 1999, Empower RF Systems is a U.S.-based company and global leader in power amplifier solutions that are critical to defense, commercial, and industrial market applications. Investments in both hardware and software engineering are yielding next generation products with significant size, weight, and interface functionality advantages over legacy products in the market.​

Erzia Technologies S.L. | 1-202-899-9709 | Washington, DC | 0034 942 29 13 45 | Santander, Spain
Wireless communications and RF equipment supplier for space and satellite communications, specializing in developing and manufacturing custom equipment for specific requirements, systems design & integration.

everything RF | 312-436-0084
Find RF & microwave components, equipment and services - 216,401 products from over 1143 manufacturers listed in 275 categories. Download hundreds of vendor white papers. Test equipment amplifiers, antennas, attenuators, bias-Ts, & terminations, RF connectors & adapters, RF filters, power combiners, couplers, & dividers, RF switches, waveguide, Bluetooth & RFID.

Exodus Advanced Communications | 702-534-6564 | Las Vegas, NV
Manufacturer of RF power amplifiers ranging from 500 kHz to 51 GHz with various output power levels and noise figure ranges. Custom designs and manufacturing requirements for both small and large volume levels. Experience in military jamming, communications, radar, EMI/EMC and various commercial projects with all designing and manufacturing of our HPA, MPA, and LNA products in-house.

Herley | 717-735-8117 | Lancaster, PA
Amplifiers, attenuators, modulators, power dividers, oscillators, synthesizers, phase shifters, switches.

Herotek | 408-941-8399 | San Jose, CA
GaAs FET amplifiers, low-noise, small signal & power 0.01 to 50 GHz, limiters, detectors, switches, harmonic generators.

High Sierra Microwave | 530-644-3393 | Camino, CA
Designs and builds PLL signal sources, up/down converters, low noise amplifiers, and comb marker generators (weak signal sources). Also provides RF/microwave test/measurement services, such as phase noise measurements to 40 GHz

Hittite Microwave Corp | 978-250-3343 | Chelmsford, MA
Amplifiers, attenuators, frequency multipliers, mixers, modulators, prescalers, switches, VCO's.

HXI | 978-772-7774 | Harvard, MA
A subsidiary of Renaissance Electronics, is a leading supplier of millimeter-wave products including LNAs, power amplifiers, mixers, detectors, oscillators, switches, transmitters, receivers and transceivers for radars, communications systems and sensors. Digital radios, mm-wave, E-band, and isolators. Standard components and custom-engineered products at the sub system level in the 18 to 110 GHz range. Also manufacture complete 60 GHz, E-band products, digital radios and mm-wave products for enterprise and back-haul applications.

Integrated Device Technology (IDT) | 800-223-1366 | San Jose, CA
System-level solutions that optimize applications with products in RF, timing, wireless power transfer, serial switching, interfaces and sensing solutions are among the company's broad array of complete mixed-signal solutions for the communications, computing, consumer, automotive and industrial segments. These products are used for development in areas such as 4G infrastructure, network communications, cloud datacenters and power management for computing and mobile devices.

Instruments for Industry (IFI) | 631-467-8400 | Ronkonkoma, NY
Amplifier configurations such as tetrode tubes, TWTs, klystrons, and solid state devices. Standard horn antennas and TEM cells.

Isotec | 516-780-2766, USA | 82-2-2040-6176, Korea
Designs, develops and manufactures extensive line of RF/microwave connectors, cable assemblies, attenuators, terminations, couplers, filters, surge protectors, and LNAs. Low PIM designs available.

KMW | 800-832-0569 | Cerritos, CA
AMBA (Active Multi Beam Antenna System), amplifiers, arrestors, attenuators, combiner | dividers, connectors, couplers, duplexers, filters, isolators/circulators, phase shifters.

L-com | 800-341-5266 | North Andover, MA
Products include cable assemblies, adapters, connectors, lightning protectors, patch panels/racks, bulk cable, RF filters & splitters, media converters, switches, power supplies, RF amplifiers, enclosures.

Linear Technology | 800-454-6327 | Milpitas, CA
Designs, manufactures and markets a broad line of standard high performance integrated circuits; principal product categories include amplifiers, battery management, data converters, high frequency, interface, voltage regulators and voltage references.

Linwave Technology Ltd | +44 1522 681811 | Lincoln, UK
RF and microwave design and manufacturing company with specialist knowledge in module and sub-system design. Our experience encompasses the consumer, industrial, automotive and defense market sectors. SATCOM BUC, SSPA, Military microwave sub modules.

Locus Microwave (now CPI) | 814-466-6275 | Boalsburg, PA
Amplifiers, SSPAs, LNAs, feed-forward, ultra low Noise amplifiers, high dynamic range amplifiers, design & manufacture, serving commercial and military markets.

Lotus Communication Systems | 888-236-8588 | Weston, MA
RF modular system components up to 20 GHz - amplifiers, filters, attenuators, limiters, oscillators, bias-Ts. COTS shielded enclosures w/SMA connectors for RF / electronics prototyping. Customization to your specification from prototype to production.

M/A-COM (now Cobham) | 800-366-2266 | Lowell, MA
Developer and high-volume manufacturer of RF, microwave and millimeter wave semiconductors, components and technologies including diodes, semiconductors, transistors, passives, blocks, substrates.

Marki Microwave | 408-778-4200 | Morgan Hill, CA
Amplifiers, converters, couplers, DC blocks, dividers, doublers, fiber-optic devices, mixers, waveguide.

Maxim Integrated Products | 800-998-9872 | Sunnyvale, CA
Amplifiers, comparators, analog switches, multiplexers, analog filters, linear and mixed-signal integrated circuits, power supplies, battery management, RTCs, clocks, oscillators, delays, counters, fiber optic ICs.

MCLI | 800-333-6254 | St. Petersburg, FL
Power dividers, couplers, isolators, circulators, waveguide components, oscillators, filters, hybrids, attenuators, switches, terminations, amplifiers.

Microwave Amplifiers | +44 (0) 1275 853196 | England
GaAs FET microwave amplifiers & subsystems for research, industrial, military and commercial applications. Amplifier frequency range from 0.8 - 20 GHz with power outputs of up to 200 W (+53 dBm).

Microwave Products and Technology (MPT) | 714-316-7300 | Fullerton CA
Core capabilities include phased array components and subsystem for communication and radar. SiGe, GaN, and GaAs RF circuit design and packaging. Also information security products and managed information security services.

Microwave Resources | 909-627-4125 | Chino, CA
Amplifiers, attenuators, circulators, isolators, frequency multipliers, waveguide couplers, mixers, detectors, filters, pin switches, adapters.

Microwave Solutions | 800-967-4267 | National City, CA
Microwave amplifiers 10 MHz to 26 GHz for military and commercial industries.

MicroWave Technology | 510-651-6700 | Fremont, CA
Gain, temperature compensation and voltage regulation modules, GaAs FETs, GaAs MESFET chips, amplifiers - high linearity driver, low noise receiver, broad band general purpose.

Mid-Atlantic RF Systems | 410-893-2430 | Forest Hill, MD
Hybrid, directional couplers, switches, RF power dividers, RF amplifiers, synthesizers, distribution assembly, contract RF assembly.

MilliTech | 413-582-9620 | Northampton, MA
Antennas, quasioptical products, mixers, detectors, oscillators, amplifiers, multipliers, control components, filters, isolators, passive waveguide products, test & measurement products.

Milmega | +44(0) 1983 618004 | UK
Providers of microwave power amplifiers for RF immunity testing above 1 GHz. Octave bands, full load mismatch tolerance, low noise and harmonic levels.

Miteq | 631-436-7400 | Hauppauge, NY
Amplifiers, mixers, frequency multipliers, passive power components, solid-state switches, attenuators, power dividers, RF and IF signal processing components, oscillators, frequency synthesizers, integrated multifunction assemblies, fiber optic products, up/downconverters, test translators, IF/video equalizers, redundancy switchover units, video modulators and modems.

Nanowave Technologies | 416-252-5602 | Canada
Thin film substrates, RF and electro-optic components (capacitors, resistors, attenuator pads) and subsystems (amplifiers, transceivers, transmitters).

National Semiconductor (now Texas Instruments) |
800-272-9959 | Santa Clara, CA
A/D converters, amplifiers, CRT, flat panel displays, IC solutions, DC/DC converters, regulators.

Nextec Microwave & RF | 408-727-1189 | Santa Clara, CA
Broadband power, low noise amplifiers, frequency multipliers and OC-192 modulator driver amplifiers for RF, microwave, mm-wave, commercial, military & fiber optic applications.

Norden Millimeter | 530-642-9123 | Placerville, CA
Microwave & Millimeter wave components from 500 MHz to 110 GHz, amplifiers, frequency multipliers, up/down converters, filters, oscillators, integrated assemblies.

NuWaves | 513-360-0800 | Middletown, OH
Broad range of design and engineering services related to the development and sustainment of key communications, telemetry and electronic warfare systems, as well as a complete line of commercially available RF products, including wideband frequency converters, high-efficiency and miniature solid state power amplifiers and bidirectional amplifiers, high intercept low noise amplifiers and miniature RF filters.

OPHIR RF | 310-306-5556 | Los Angeles, CA
Amplifiers, RF & microwave, broadband high power, communication band high power, solid state amplifiers.

Orban Microwave (OMP) | 915-590-0825 | El Paso, TX
Frequency converters, power amplifiers, low noise amplifiers, local oscillators, patch antennas, parabolic antennas and antenna arrays for WLAN, GPS, cellular, point to point, satellite and other applications.

Parsec Technologies | 972-804-4600 | Plano, TX
Amplifier chips for various wireless and mobile antenna markets. HDTV, M2M, LTE, GPS, WiFi, CATV / broadband, VHF / UHF, digital audio broadcast (DAB), macro cell & small cell, cognitive radio, software defined radio (SDR), & TV whitespace.

Pascall Electronics | +44 (0) 1983 817300 | UK
Amplifiers, mixers, attenuators, switches, oscillators, couplers, IQ networks.

Picosecond Pulse Labs (now Tektronix) | 303-443-1249 | Boulder, CO
Amplifiers, drivers, attenuators, baluns, transformers, bias tees, comb generators, custom pulse generators, DC blocks, driver/controller modules, ECL/PECL terminators, edge compressors, impulse forming networks, low-pass filters, power dividers, pulse generators, sampler modules TDR/TDT instruments.

Planar Monolithics Industries | 301-662-5019 | Frederick, MD
PMI designs, develops, manufactures, tests, and markets hybrid RF/microwave and monolithic integrated circuits (MIC/MMIC) and components hybrid MIC/MMIC supercomponents and subsystems.

Princeton Microwave Technology | 609-586-8140 | Mercerville, NJ
Manufacturer of high quality DRO, PLDRO oscillators, coaxial resonator oscillators, Military & SATCOM amplifiers, power dividers, phase noise measurement systems, phase shifters and transmit receive modules, phase locked YIG frequency synthesizers.

Pro-Comm | 732-206-0660 | Brick, NJ
RF amplifiers, triode cavity oscillators, sources, transmitters, test equipment for cellular, military, medical, sterilization, for university and private labs. 600-3000 MHz, 500 W peak to 50 kW peak nominal. Design, manufacture and service RF drivers. Repair/refurbish medical RF drivers manufactured by SPC, MPD, Titan Beta, Micon, Siemens, SGS Thomson, Varian, Comtech, Pro-Comm.

Q-Bit (now API Technologies) | 888-553-7531 | Palm Bay, FL
Amplifiers, mixers and VCOs. 750 datasheets to choose from with customizations requested. Industry standard packages, aggressive lead times and great customer service.

QORVO (formerly RFMD)| 336-664-1233 | Greensboro, NC
Supplier of low-cost, high-performance integrated circuits and solutions — enabling wireless connectivity inlc including radio components and solutions for cellular, WLAN, Bluetooth® wireless technology, GPS and infrastructure.

QuinStar Technology | 310-320-1111 | Torrance, CA
Designs and manufactures millimeter-wave products for communication, scientific, and test applications including millimeter-wave products, microelectronic assembly, rapid prototyping, and mass customization. Amplifiers, receivers, oscillators, switches, attenuators, circulators & isolators, filters, waveguide, antennas, and phase shifters, and transceiver & radar subsystems.

Quintech | 800-839-3658 | Indiana, PA
Designs and manufactures state-of-the-art proprietary hardware solutions (DC to 40 GHz) to facilitate RF signal management for Satellite uplink and downlink applications in satellite teleports, cable HFC headends, broadcast, wireless and military telecommunications networks.

RFHIC Corp USA | 919-342-7099 | Cary, NC
CATV hybrid line amplifiers, broadcasting amplifiers, FTTH amplifiers, digital TV application, MMIC (GaN, GaAs), high power transistors (GaN), low noise, wideband, & radar pallet amplifiers, PLLs, mixers, directional couplers

RF HiTec | 82-2-999-4601 | Seoul, Korea
Super linear and high power single/multi-carrier power amplifiers for use in PCS | DCS | GSM | CDMA | IMT2000 | WLL applications for frequency bands from 450M to 2.7G, LNAs, mini-LNA, U/D converter and other RF components.

RFMD (now QORVO) | 336-664-1233 | Greensboro, NC
Supplier of low-cost, high-performance integrated circuits and solutions — enabling wireless connectivity inlc including radio components and solutions for cellular, WLAN, Bluetooth® wireless technology, GPS and infrastructure.

Rohde & Schwarz | 888-837-8772 | Columbia, MD
Test & measurement, radio communications, broadcasting, antennas, IT security, signal intelligence, spectrum monitoring, trunked radio. RF signal generators, spectrum , network, and communications analyzers, digital and mixed signal o-scopes, power and field strength meters, amplifiers, frequency counters, arbitrary waveform generators.

Roswin | 82-41-621-4450 | ChungNom, Korea
Products include phase locked loop modules, voltage controlled oscillators, low noise amplifiers, high power amplifiers, dielectric filters, LC filters & UDC modules.

SHF Communication Technologies
+49-30-772-051-23 | Germany
Adapters - 3.5mm, 2.4mm, 2.92mm, 1.85mm, amplifiers (DC to > 50 GHz), connectors - 1.85mm, 2.92mm, optical transmitters, receivers, phase shifters, test equipment pattern generators, error analyzer, multiplexer, demultiplexer, clock recovery, bias tees, DC blocks, monitor tee, power dividers.

SIEL Srl | +39 02 45713300 | Italy
Specializes in the design and production of professional FM broadcasting equipment including FM exciters and solid-state FM amplifiers up to 20 KW, stereo and RDS encoders, control systems, analogue and digital radio links.

Sirenza Microdevices (now RFMD now QORVO)
336-664-1233 | Greensboro, NC
Designer & manufacturer of RF components serving existing and emerging wireless and wireline markets, offering a wide range of innovative RF solutions for transmitter, receiver and transceiver designs including amplifiers, transistors, mixers, modulators, VCOs, PLLs, demodulators, stripline couplers, transformers.

Skyworks Solutions | 781-376-3000 | Woburn, MA
RF amplifiers, attenuators, circulators, demodulators, detectors, diodes, directional couplers, FEMs, RF subsystems, isolators, mixers, modulators, optoisolators, phase shifters, PLLs-synthesizers-VCOs, & more.

Spacek Labs | 805-564-4404 | Santa Barbara, CA
Amplifiers, filters, mixers, multipliers, oscillators, block downconverters.

Teledyne Cougar | 408-522-3838 | Sunnyvale, CA
RF and microwave cascadable amplifiers and subsystems in 100 kHz to 12 GHz range. Detectors, limiters, limiting amplifiers, attenuators, AGC amplifiers, oscillators w/MMIC amplifiers.

Texas Instruments | 800-477-8924 | Dallas, TX
Op amps, audio amplifiers, clocks & timers, data converters , logic ICs, interface IC and connectivity solutions, power management, processors, RFID systems, RF/IF & ZigBee® solutions, switches & multiplexers.

TMD Technologies Ltd | +44 (0)20 8573 5555 | UK
Suppliers of rugged amplifiers and transmitters for radar and electronic Warfare (EW) applications, as well as microwave tubes, high voltage power supplies, instrumentation microwave amplifiers and special processing services.

Toko | 847-297-0070 | Mt. Prospect, IL
Filters, baluns, inductors, antennas, semiconductors, amplifiers, A/D converters.

Tomco Technologies | (618) 8364 2203 | Adelaide, Australia
Design and manufacture of solid-state RF power amplifiers, pulsed and CW, 10kHz to 600MHz.

Triad RF Systems | 732-310-9918 | East Brunswick, NJ
Your source for RF front ends, transceivers and amplifier systems that just plain work! Solutions for integrating high performance HPAs into sophisticated RF subsystems and systems without sacrificing efficiency and linearity.

Triquint Semiconductor | 503-615-9000 | Hillsboro, OR
Wireless, telecom and millimeter amplifiers, GaAs integrated circuits and transistors. SAW filters.

Tugicom | + 972 - 98615533 | Netanya, Israel
FM transmitters (up to 300 W), receivers, power amplifiers, RF modules, stereo encoders, filters.

Wessex Electronics (now Amplifier Technology Ltd, now Vislink) | 0117 957 1404 | UK
RF & Microwave amplifiers, microcircuits, phase shifters, 26-40 GHz LNAs & downconverters, microwave synthesizers, test & measurement.

Windfreak Technologies | 727-490-8812 | Holiday, FL
Designs, manufactures, tests and sells high value USB powered and controlled RF signal generators, synthesizers, power detectors, mixers, Upconverters and downconverters.