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Combining multiple attenuators into a single unit gives a more compact design and
Note: This is a sampling of the beginning
of an application note by JFW Industries titled "An Introduction to Programmable Attenuator Systems." Please click
the hyperlink for the complete document.
An attenuator is an electrical component that reduces the amplitude of a signal passing
through it without significantly degrading the integrity of that signal. In a programmable
or step attenuator, the attenuation is controlled externally by an external analog or
digital signal, either manually or via a computer. Depending on the model, the maximum
attenuation ranges from 0 dB to 127 dB, in steps as small as 0.1 dB. The
attenuator is controlled by a combination of digital inputs, an analog voltage or via
USB, RS-232, Ethernet or GPIB. These devices are bi-directional, so either port can act
as an input or an output.
JFW produces many programmable attenuators and attenuator systems for different applications.
This article will review the key components of a programmable attenuator system and discuss
the best choices for some common applications. Figure 1 shows several JFW programmable
Applications for Programmable Attenuator Systems
Figure 1: A selection of programmable attenuators ranging from a single
unit (left) to a limited-fan-out 24-port transceiver test system (right). Source: JFW
Programmable attenuators test and evaluate the performance of many wireless applications:
- Military radios
- First responder networks
- Wi-Fi/MU-MIMO • Cellular networks
- Mesh networks (ZigBee, LoRa, etc.)
- Emerging IoT/5G systems
The key specifications of a programmable attenuator include:
The frequency range
The VSWR (voltage standing wave ratio), a measure of how efficiently RF power is transmitted
through the attenuator
The attenuation range and step size
The characteristic impedance (usually 50 or 75 Ω)
Click here for the entire "An Introduction to Programmable Attenuator Systems" application note.
About JFW Industries
Founded in 1979 in Beech Grove, Indiana, JFW Industries Inc. is a world leader in
designing and manufacturing passive RF components and application specific test systems.
These components include attenuators, RF switches, and specialized test systems for use
in the cellular, telecommunications, OEM test equipment, medical, automotive, defense,
and automated test markets. Innovative new designs and a focus on customer requirements
have allowed JFW to maintain steady growth in many key market segments.
JFW has over 100 dedicated employees, diligently working to ensure quality assembly
and on-time delivery. Each one of our dedicated employees represents our over 30-year
commitment to providing reliable RF solutions. Beginning with an industry renowned Customer
Service Department, everyone at JFW strives for complete customer satisfaction by responding
to the needs of each customer individually and providing the RF component or system that
best suits that customer's application.
JFW is an ISO-9001:2008 registered company. We have over 14,000 square feet of design
and manufacturing space, located in Indianapolis, Indiana (USA) with a European office
located in England. JFW is equipped for most facets of the design, assembly, integration
and testing of RF technologies
JFW Industries, Inc.
5134 Commerce Square Drive
Phone: 317 887-1340
Posted December 6, 2017