Timothy Shroyer, Vice President of
Business Development at TriPoint Global Communications, offers a
roadmap for improved Earth Station design and performance in a
technical article appearing this month in "Base Station Earth
Station" magazine.
"In recent years,"
Shroyer said, substantial advances have been made in earth station
architecture to achieve dramatic increases in performance while
keeping costs extremely low.
"One of the most significant
developments is the use of the Low Noise Block Converter (LNB) to
replace the Low Noise Amplifier and the first down converter stage
used in traditionally-designed Earth Stations. LNBs permit the use
of coaxial Inter-Facility Links and also allow the remaining down
converter synthesized Local Oscillator stages to be implemented at a
much lower frequency. The result is reduced complexity and
cost."
"In the uplink chain,"
Shroyer added, "a similar evolution has taken place with the
development of sophisticated, low-cost high performance Block
Up-Converters or BUCs.. In addition, high performance L-Band up
converters and down converters use frequency synthesizers produced
in high volume for cellular and PCS applications with very
cost-effective results. Local oscillator phase noise is
substantially better than the Intelsat IESS-308 and IESS-309
standards. This means that the same or higher level of phase noise
and spurious performance can be achieved at a much lower cost."
The VertexRSI LT-3000 series of up
and down converters is a good example of this new class of
converters. Housed in a low-profile 1U (1.75in) chassis, the
VertexRSI LT-3000 Up/Down Converter is a convenient, low-cost
solution for systems requiring a 70 MHz (or optional 140 MHz) to
L-Band interface. Each of the independently synthesized up and down
converters use a dual-stage conversion design to deliver
high-performance over a full 575 MHz bandwidth. Both the up and down
converters can feed DC power and a 10 MHz reference out of the
transmit or receive ports to supply either a phase-locked BUC or LNB.
When combined with a VertexRSI C-,
X-, or Ku-Band solid-state power amplifier, BUC and LNB the LT-3000
converter provides a high-performance, cost-effective transceiver
solution for a variety of communications systems.
"I believe the L-Band
architecture is the hands-down winner for new and improved Earth
Station designs," Shroyer said.
"L-Band architecture has
already significantly reduced the price for high level performance.
In the final analysis, the question is not whether you can afford to
move to the new architecture, but whether you can afford not
to."
Shroyer's complete article may be
viewed at the Base Station Earth Station web site: http://www.base-earth.com/july-august2003/tripoint.html
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