|
 Circulators and
isolators are very handy (and necessary) devices for use when it is essential to
keep RF signal flow in one direction only. Think of them loosely as a steering diode
array that directs energy from one port to a specific other port (or ports). Circulators
and isolators (an isolator is basically a circulator with the third port terminated
in the characteristic impedance) are fundamentally 3-port devices with 120° between
ports. Ferrites with special properties (known only to the sworn circulator designer
brotherhood) affect the directional control. Here is a brief
circulator application
note from MECA Electronics.
One important thing to keep in mind is that specified values for isolation are
only guaranteed at 50+j0 ohms, or whatever the characteristic impedance of the attenuator
model happens to be (50 and 75 ohms most common). The farther away from the characteristic
impedance the connected ports are, the farther from the spec the isolation value
will be.
 
AFT Microwave | +49 7191 9659
0 | Germany
Microwave components including circulators, isolators, waveguide and coaxial
components, phase shifters, ferrites, thin film technology.
Advanced Technical Materials (ATM)
| 631-289-0363 | Patchogue, NY
Attenuators, bias tees, coaxial cables, couplers, DC blocks, isolators, circulators,
line stretchers, noise sources, phase shifters, power dividers/combiners, switches,
terminations, waveguide, adapters, horn antenna.
Aerotek Company | 662-332-5035,
311-4448 | Thailand
Coaxial, drop-in, lump, drop-in lump, flange mount circulators & isolators,
88 MHz - 18 GHz.
Cernex | 408-541-9226 |
Sunnyvale, CA
Amplifiers, antennas, couplers, isolators, circulators, filters, diplexers, oscillators,
noise sources, switches, phase shifters, transition & adapters, mixers, waveguide
products, attenuators, terminations, detectors, subsystems.
Channel Microwave
| 805-482-7280 | Camarillo, CA
Coaxial and waveguide isolators, circulators, ISO-adapters, integrated assemblies,
filters, terminations.
Charter Engineering
| 727-549-8999 | Largo, FL
Electromechanical switches, attenuators, isolators, terminations, circulators,
power dividers, couplers.
Corry Micronics | 724-940-7556
| Corry, PA
Dielectric resonators, bandpass filters, LC filters, VCOs, PLLs, patch antennas,
power dividers, connectorized lumped element power dividers, directional couplers,
isolators/circulators, high power hybrids, diplexers & multiplexers, attenuators,
switches, cavity filters, waveguides, standard gain horn antennas.
Crane Aerospace &
Electronics - Microwave Solutions | West Caldwell, NJ 973-575-1300
RF, IF and millimeter-wave components, subsystems and systems for commercial
aviation, defense, and space. Integrated assemblies include beamformers, oscillators,
frequency converters and switch matrix systems, and amplifiers. Microwave circuit
board substrates, non-magnetic capacitors. Space qualified circulators, isolators,
mixers, couplers, power dividers, and much more.
DiTom Microwave | 559-255-7045 | Fresno,
CA
Connectorized single and dual junction ferrite isolators and circulators for
the space and defense markets. COTS and Hi-Reliability products available covering
700 MHz to 31 GHz.
Dorado International
| 206-574-0900 | Seattle, WA
Planar, horn, 8.2 GHz to 110 GHz antennas, waveguide isolators & circulators,
switches, adapters, connectors.
EM Design, LLC | 541-878-3927
| Shady Cove, OR
Specializes in the design and fabrication of RF and microwave components, systems
and sub-systems including antennas, antenna polarizers, circulators, isolators,
waveguide loads, coaxial loads, microwave pulse compressors, waveguide windows,
waveguide seals, waveguide shorts, waveguide couplers and microwave heating.
EMR Corporation | 800-796-2875
| Phoenix, AZ
RF peripherals devices from 30 MHz to 2.8 GHz. Design, manufacture and systems'
engineering for RF isolators, amplifiers & BDAs, filters - band pass & band
reject, mobile & base station duplexers, combiners - cavity ferrite & hybrid
ferrite, RX multicouplers and accessories including LNAs.
Ferrite | 603-881-5234
| Hudson, NH
Circulators, isolators, transmitters.
Filtel | 450-455-6082 |
Canada
Couplers, power dividers, isolators, coaxial & waveguide circulators.
Innertron | +82-32-816-1456
| Incheon-City, Korea
A wide selection of RF & microwave components as well as power dividers,
power splitters, arrestors, bias-Ts, attenuators, terminations, directional couplers
which cover the frequency range from DC to 18 GHz. Waveguide filters, diplexer,
adaptor, couplers up to 40 GHz, custom designs are available to support applications
for the military and commercial industries.
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.
Kete Microwave Electronics
| +86-595-22597735 | China
Ferrite RF isolator & circulators, high power RF resistors & terminations,
fixed & variable/step attenuators, multilayer High-Q chip ceramic& feedthrough
capacitor (EMI filters), directional couplers, power dividers / combiners, 3dB hybrid
couplers.
JQL Electronics
| 888-236-9828 | Rolling Meadows, IL
Manufacturer of RF and microwave devices including filters, isolators & circulators,
directional couplers, power divider/combiners, hybrid, termination and etc. Our
R&D team provides outstanding services to quickly bring your product concepts
into prototype, and turn the prototype into products.
MCLI | www.800-333-6254 |
St. Petersburg, FL
Power dividers, couplers, isolators, circulators, waveguide components, oscillators,
filters, hybrids, attenuators, switches, terminations, amplifiers.
MECA Electronics | 866-444-6322
| Denville, NJ
RF & microwave components for in-building, satellite, radar, radio, telemetry,
mobile radio, aviation & ATC. Attenuators, directional & hybrid couplers,
isolators & circulators, power dividers & combiners, loads, DC blocks, bias-Ts
and adapters & cables.
Mica Microwave (now Mercury
Systems) | 209-825-3977 | Manteca, CA
Circulators, isolators, mixers, equalizers, phase shifters.
Microwave Devices |
888-736-8837 | Franklin, IN
Attenuators, terminators, directional couplers, filters, isolators/circulators,
cable assemblies, measurement equipment.
Microwave Resources
| 909-627-4125 | Chino, CA
Amplifiers, attenuators, circulators, isolators, frequency multipliers, waveguide
couplers, mixers, detectors, filters, pin switches, adapters.
Microwave Technology Corporation
(MTC) | +66-35-721-559 to 60 | Wang-noi, Thailand
Microwave passive components of isolators & circulators including coaxial
from 80 MHz to 40 GHz. Drop-in or surface mounted from 400 MHz to 20 GHz. Waveguide
is up to 40 GHz. Power up to power rating 500 W. Additional product waveguide adaptor &
termination.
Murata Electronics | 800-241-6574
| Smyrna, GA
Chip multi-layer (1.0 2.5 GHz), chip dielectric (2450 GHz, Bluetooth), surface
mount capacitors, thermistors/resistors, coil (inductors)/delay lines, noise suppression
products/EMI filters, resonators, piezoelectric sound components, coaxial connectors,
antenna/duplexers, isolators/circulators, PLL modules, VCOs, TCXO, RF diode switches,
DC-DC converters, sensors.
Nanowave | +82-43-903-4828
| South Korea
SMD, drop-in, coaxial, waveguide isolators, circulators, directional, hybrid
couplers, 2way, 3way, 4way dividers, attenuators, terminations.
Nova Microwave |
408-778-2746 | Clearwater, FL
RF ferrite circulators and isolators that connect, protect and control critical
commercial and military wireless telecomm systems. Standard and custom design quality
circulators and isolators from 380 MHz to 26.5 GHz.
Pasternack Enterprises
| 866-727-8376 | Irvine, CA
Amplifiers to 2 GHz, attenuators 1 - 1000 W DC - 40 GHz, circulators/isolators
1 - 26.5 GHZ w/SMA connectors, combiners/dividers 2 - 12 way 1 MHz - 18 GHz, couplers
low & high power 0.5 - 18 GHz, switches manual & diode DC - 18 GHz, terminations
1/2 - 100 W DC-40 GHz, waveguide 1.70 - 40 GHz.
Quantum Microwave
| 857-499-0071 | Cohasset, MA
Millimeter-wave waveguide components including attenuators, detectors, diplexers,
power amplifiers, mixers, isolators & circulator, multipliers, antennas, switches,
probe adapters, terminations, and filters. Waveguide sections include straight,
bends, twists, transitions, and adapters. Patented "GuideLock" connector eliminates
screws. Cryogenic components available. Designed and manufactured at their Massachusetts
facility.
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.
Raditek | 408-266-7404
| San Jose, CA
Isolators, circulators, oscillators, synthesizers, couplers, splitters, combiners,
hybrids, adaptors, cable assemblies, connectors, terminations, attenuators, bias
tee's, lightning protectors.
Renaissance Electronics
| 978-772-7774 | Harvard, MA
Manufacturer of RF & microwave sub-systems and components including isolators &
circulators, dividers & combiners, waveguide components, coaxial RF switches,
switch matrices, base station equipment.
RF & Noise Components
Ltd | +44 (0) 5601 06 69 30 | Southend-on-Sea, Essex, UK
Design & manufacturer of RF & microwave components including circulators,
isolators, combiners, couplers, dividers and power monitors. Specialising in custom
designs to meet individual customer requirements. ISO9001:2008 Approved.
RF-Lambda | 613-592-6858
| Canada
Couplers, circulators, isolators, mixers, attenuators, coupler, power amplifiers,
LNA, VCO, switches, oscillators, connectors, adapters.
RTx Technology Co., Ltd
| +82-31-743-6275 | South Korea
Filters, duplexers, multiplexers (ceramic/cavity), VCOs & PLL synthesizers,
isolators & circulators, up/down converters, combiners & dividers, directional
couplers, SAW devices, attenuators, terminators.
Trak Microwave | 888-283-8444
| Tampa, FL
Attenuators, circulators, isolators, comb generators, control devices, couplers,
delay line filters, GPS time & frequency, hybrids, IQ mod & demod, mixers,
multipliers, oscillators, phase shifters, splitters & combiners, synthesizers,
transformers.
Vector Telecom | +61
3 9607 8357 | Melbourne , Australia
Waveguide components and assemblies, coaxial components and antennas.
vidaRF | www.877-777-8432
| Huntersville, NC
Offering High performance isolators, circulators, power dividers, couplers, RF
connectors, adapters, custom cable assemblies, attenuators, and terminations. Custom
designs available. In-stock items shipped within 24 hours.
VivaTech | +1 818 547
5036 (USA) | +44 750 923 3838 (Intl Mobile)
System front-ends, mm-wave test equipment, source modules, amplifiers, active
multipliers, mixers, frequency converters, frequency extension modules, radiometer
front-ends, waveguide isolators, waveguide attenuators, passive and active waveguide
components and primary noise standards.
Wisewave Technologies (now
Ducommun Technologies) | 310-513-7200 | Carson, CA
Amplifiers, antennas, attenuators, PIN diode switches, phase shifters, isolators/circulators,
frequency converters, oscillators, couplers, magic tees, coax power dividers, bandpass,
low pass, high pass filters, waveguide diplexers, transitions, waveguide to coax
adapters, waveguide components, integrated assemblies.
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