Better Value for
RF & Microwave Components
Home > Support > FAQ

Frequently Asked Questions (FAQ) for Fixed Attenuators

Below are Frequently Asked Questions about RF ONE’s fixed attenuators. If you need more information or have any other questions, please feel free to e-mail us at or call us at 86-755-86705630. We will be very happy to assist you.

Does RF ONE offer low PIM attenuators?
Almost all of our catalog attenuators (RFH/RFHB series) meet the min PIM -110dBC, typical -115dbc (measured at 1800MHZ, 2*20W or 2*10W depending on the attenuator’s rated power). Min PIM -120dBc attenuators are available by screening.
If customer needs lower PIM level such as 140dbc, 150dbc, 160dBC, please visit our website page Low PIM Passive Components, where we specially list the low PIM attenuators, terminations, duplexers etc.

Can RF ONE provide conduction cooled attenuators?
If not specified otherwise, the attenuators on our catalog is self-cooled.
We also offer convection & conduction combined cooled attenuators with custom package size. For example, to suit customer’s mounting rack, we have built 150W and 250W attenuators with flat bottom (refer to below photo).
When customer needs purely conduction cooled attenuators without any heat sink, check with our sales for your specific requirements.
conduction cooled attenuators
What attenuation values can RF ONE build?
We have been building ceramic attenuator chips in-house since 2002. Technically all dB values can be built.
RF ONE has shipped 0/1/2/3/4/5/6/7/8/9/10/11/12/13/14/15/20/30/40/50/60dB attenuators. But please check with our sales if certain dB is available in stock for a selected model.

Does RF ONE provide both directional and bi-directional attenuators?
Bidirectional attenuators means the maximum rated power can be applied to either the input or output.
Unidirectional attenuators means the maximum rated power can only be applied to the input port. Unidirectional designs features smaller overall package sizes and reduced costs.
We have clearly specified the attenuator’s direction on the datasheet. 2W till 25W by default are bi-directional. 30W-100W are available in both uni-directional and bi-directional types.
RF One always laser mark IN/OUT on the uni-directional attenuator ports.

What special attenuators are available from RF ONE?
RF ONE has high flexibility to offer customized attenuators. The special designs include but not limited to the below list:
1. Custom mixed connector Configurations, for example, 4.3-10 male as output, N female as input.
2. Rare attenuation values such as 0dB, 11db, 13dB etc. are offered with no additional charge.
3. Lower VSWR & higher accuracy in a specified frequency range.
All of our attenuators are tested in VSWR and accuracy, test plots are provided for each shipment. If improved VSWR and accuracy are desired, contact our sales with your specific requirements.
4.Custom mounting holes or heat sink sizes available
5.Private label, customized laser markings available.

What resistors are applied to RF ONE’s attenuators?
Our DC-18GHZ attenuator chips are built from thick film processing.
Our DC-27G/40G/50G/67G attenuators use aluminum nitride chips which are by thin-film processing.
We only choose resistive and insulating materials with a similarly low CTE which can reduce the effect of significant reflections due to impedance change at high temperature.
High temperature firing technology on the chips (usually greater than 900 degree) is used to produce a reliable connection between paste and substrate, which results in a long-lasting high stability over temperature as well as over power and time.

What are the temperature coefficient of RF ONE’s attenuators?
Among the RF ONE’s vast fixed attenuator family which covers a frequency range of DC to 67GHz, and the power handling ranges from 2 watts to 2000 watts, the temperature coefficient is specified as 0.0003dB/dB/°C

Does RF ONE use Pi-pad or T-pad layout for the attenuator chip?
For the range of DC-18GHZ, 2W-500W attenuator, we use both Pi and T designs according to the attenuator's frequency range, dB value and power rates. Normally T layout produces a better frequency response in the case of smaller dB value, but the VSWR is worse. For the range of DC to 40GHZ till 67GHZ attenuators, we only use distributed PI network.

What is the warranty of RF ONE’s attenuators?
All high power attenuators (100W and higher) are warranted 12 months since ship date. Check our Terms and Conditions for detailed warranty policy.

What are the distinguishing advantages of RF ONE’s attenuators?
1.RF ONE’s fixed attenuators have no solder contacts. We use spring loaded plunger contacts to the resistor cards that provide expansion tolerance over wide temperature and power ranges.
2. RF ONE only uses high quality stainless steel or brass materials for the connectors which are machined to tight tolerances. The center contact pin is gold plated BeCu according to MIL-G-5024 to ensure reliable multiple matings.
3. Typical delivery for our catalog attenuators are 1 week delivery.
4. RF One offers the widest selection of coaxial fixed attenuators with 0-60db, DC-67GHZ.