29-06-2013, 04:41 PM
L-Band Block Upconverter (BUC)
L-Band Block.pdf (Size: 258.13 KB / Downloads: 175)
Introduction
The basic architecture of a conventional satcom terminal is derived from the historical
desire to keep the design and supply of the hardware items as free and open as possible.
Over the years, this concept has promoted global competition at every functional
hardware block, and has dramatically improved designs and reduced costs to the end
user. However, as operating requirements change and technology advances, system
architecture must be modified to take advantage of the additional cost and performance
benefits that can be realized. A CPI amplifier with an integrated L-Band Block
Upconverter offers the opportunity for significant cost and reliability savings in low and
medium data rate applications by eliminating costly duplicated functions in the
conventional RF terminal chain.
CPI (formerly Varian Electron Device Group) has been active in the design and
manufacture of microwave power amplifiers and related products for more than 30 years.
CPI Satcom Division (formerly Varian MEP) was organized in the mid-1970s to bring
together, under a single business operation, the strengths of existing groups involved with
commercial Satcom and Industrial power amplifiers.
Since then, CPI Satcom Division has provided thousands of fully integrated satellite
uplink power amplifiers in the S, C, X, Ku, DBS and Ka- band frequency ranges to users
worldwide and has become the leading supplier of this class of products.
Description
L-Band input starts at the lower end point of 900 or 950 MHz, and stretches from 500 to
1100 MHz. Please take care to ensure that the proper L-band frequency range is not
exceeded or damage may result. The signal must be free of spurious signals that can
cause poor performance or even cause the amplifier to fail. The L-band input signal can
be translated to the following microwave bands:
• 5.850 – 6.425 GHz
• 5.85 – 6.65 GHz
• 5.850 – 6.725 GHz
• 7.9 – 8.4 GHz
• 14.0 – 14.5 GHz
• 13.75 – 14.50 GHz
• 12.75 – 13.25 GHz
• 17.3 – 18.1 GHz
MUX Reference:
Most L-band modems now have a built-in 10 MHz reference. The CPI
BUC can be configured to accept this reference, which is multiplexed with the L-band
signal on the same connector. This is CPI’s standard configuration, and is recommended
for most applications. The MUXed 10 MHz reference must be in the range of -5 to +5
dBm to stay in lock. Care must be taken not to attenuate this signal below -5 dBm when
controlling the L-band input. To control the power level use the internal HPA attenuator,
which will not affect the 10 MHz reference. A system-level power lineup will be helpful
to ensure proper operation though all levels.