Comtech EF Data LGAN, Инструкция по установке и эксплуатации

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L-GaN
Revision 0
Introduction 1–3
1.3.5 Data Logging Capability
To greatly enhance system maintainability, the LGaN includes a built-in data logging capability. By
recording critical operational parameters (such as temperature, output power, mute status, etc.) at time
stamped intervals, the user can quickly gather intelligence not only about the unit itself, but also the unit’s
operational environment.
1.3.6 Optional Internal 10 MHz Reference
With the optional high stability, oven-controlled crystal oscillator (OCXO) installed, one more signal is
removed from the Tx IF cable. This ensures optimum RF performance of the BUC by eliminating any
reference degradation caused by IF combiners, interconnections, or rotary joints.
1.3.7 Optional LNB Support
The LGaN was designed with the evolution of L-band systems in mind. L-band IF topologies are no
longer relegated to low power single carrier installations and are now found in larger multi-carrier
installations. A challenge presented by multi-carrier L-band systems is the presence of DC and reference
components on the Tx/Rx L-band interfaces. The LGaN design, by default, eliminates the DC component
from the Tx IF and can eliminate the reference requirement with the optional internal OCXO. The LNB
bias/reference option completes the solution by eliminating DC and reference signal requirements from
the Rx L-band interface.
1.3.8 SSPA Module
The amplifier module performs the core function of the unit. An isolator is at the RF input to ensure good
voltage standing wave ratio (VSWR). The RF signal then passes through an electronically controlled
attenuator that adjusts the overall attenuation according to the user input. After some amplification, a
second attenuator is automatically controlled via a look-up table to maintain the amplifier gain at a
constant level over temperature variations.
The RF signal is then amplified by a multi-stage design that utilizes proprietary combining techniques to
meet the rated power requirements. The output circuitry contains a coupler to provide a sampled signal
for monitoring purposes. A power detector circuit also is included, and the reading can be accessed via
remote communication. A high-power circulator and load are located at the output to provide good VSWR
and protection from external mismatch.
1.3.9 Cooling System
Chapter 2. SYSTEM CONNECTORS, INSTALLATION AND STARTUP
The LGaN contains a robust heat sink and thermal design to maintain a low operating temperature. All
contain temperature-controlled fans which are monitored by the M&C board. The fans draw in cool
outside air across the power supply and specialized RF heat sink. The amplifier module temperature is
monitored and, if for any reason the amplifier temperature exceeds a safe preset limit, the amplifier
module supply is shut down to protect the unit from thermal failure.
Most LGaN units monitor the ambient (outside) air temperature through a sensor located in the air intake.
An alarm is generated if the ambient temperature rises at least 3°C (37.4°F) above the specified upper
limit. Additionally, the unit will shut down to protect itself if an ambient temperature of 6°C (42.8°F) above
the specified upper limit is detected.