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Scalable
Power Amplifiers
By Jason Smith, Senior Sales Applications Engineer,
AR Worldwide
Many test labs are seeing a continued increase
in RF test levels and test distances that usually require
a larger, more powerful amplifier to replace smaller, now
obsolete amplifiers. This high field strength that required
the new larger amplifier allocates for a small portion of
the test labs' total testing time, leaving this amplifier
underutilized for most of the time. As the world moves further
and further into the digital and wireless age, the need
for flexibility of test equipment becomes a necessity. The
ability to separate out or split the amplifier for multiple
uses would be extremely beneficial to a test lab.
AR Worldwide RF/Microwave Instrumentation has responded
to this flexibility need with a new offering of Scalable
Power amplifiers. Scalable power consists of two options;
expandable power that allows customers to grow power when
needed and divided power when customers don't need the power.

In order for these amplifiers to be controlled
and to work in unison, some considerations must be met.
The amplifiers need to be combined and controlled by a central
location, a controller, and both the input and output come
from the controller. The RF input is pre-amplified and divided
through the controller; phase matched cable run to each
sub amplifier input. From the sub amplifier output, phase
matched cables return to the controller to be combined.
If these cables and sub amplifiers are not phase matched,
power losses will occur and the system will be less efficient.
The controller is the heart of the scalable power technology
and what enables AR Worldwide to increase the flexibility
of the amplifiers. The controller consists of the following
components: controller, pre-amplifier and splitter, output
combiner and power monitor. Only one controller needs to
be purchased to utilize the scalable power technology. For
example, if a user were increasing from a 450S1G3 (450 watts,
1 - 3 GHz), to a 600S1G3 (600 watts), a new controller is
not needed, only a new output combiner. A modification of
the controller is required as is a recalibration of the
automatic level control (ALC).
The following AR Worldwide amplifiers can be used as the
building blocks for scalable power:
Model 1000W1000C (1000 watts, 80 - 1000 MHz)
2 x 1000W1000C + controller = 2000W1000A
(2000 watts nominal)
3 x 1000W1000C + controller = 3000W1000
(3000 watts nominal)
4 x 1000W1000C + controller = 4000W1000
(4000 watts nominal)
Model 200S1G4A (200 watts, 0.8 - 4.2 GHz)
2 x 200S1G4A + controller = 400S1G4 (400 watts)
3 x 200S1G4A + controller = 540S1G4 (540 watts)
4 x 200S1G4A + controller = 700S1G4 (700 watts)
Model 240S1G3A (240 watts, 1 - 3 GHz)
2 x 240S1G3A + controller = 450S1G3 (450 watts)
3 x 240S1G3A + controller = 600S1G3 (600 watts)
4 x 240S1G3A + controller = 800S1G3 (800 watts)
An Example of Expandable Power
An AR model 200S1G4A (200 watts, 0.8 - 4.2 GHz) can be purchased
today; then, in the future, when specs change and more power
is needed, another 200S1G4A (phase and amplitude matched)
can be purchased with a controller to make a 400S1G4 (400
watts, 0.8 - 4.2 GHz). The bonus is that each 200S1G4A can
be separated and still function independently. The two amplifiers
can be used in different locations in the lab and when 400
watts is needed, they can be brought together and used as
a 400S1G4. Even though the system is combined, each amplifier
can still be used independently. The system can be upgraded
even more with a total of 4 independent 200S1G4A models
to 700 watts, with a modification of the controller.

An Example of Divided Power
An AR model 3000W1000 (3000 watts, 80 - 1000 MHz) can be
purchased to provide the needed 3000 watts of power, but
when 3000 watts may not be required, each of the three 1000W1000C
independent amplifiers can function separately at 1000 watts
in multiple locations. The user would need to disconnect
the controller from the amplifier and now the amplifier
can function independently.
For more information on Scalable Power or to view AR Worldwide
RF/Microwave Instrumentation's full offering of products,
please visit www.ar-worldwide.com or call an applications
engineer at 800-933-8181.
About the Author
Jason Smith is the Senior Sales Applications Engineer
for AR Worldwide. His responsibilities include EMC applications
support to customers, technical writing, and guidance for
product development. He has over 7 years EMC experience
as a lab manager and test engineer for independent EMC test
labs. He has experience testing to IEC, MIL-STD, DO160,
medical, telecom, and automotive requirements.
AR Worldwide RF/Microwave
Instrumentation
www.ar-worldwide.com
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