Comtech EF Data CPA - Manual (Page 20)

CPA C-Band Indoor Solid State Power Amplifier Revision 1
Introduction MN/CPA-IN.IOM
1-2
1.2 Functional Description
The CPA consists of a chassis, power supplies, fan assembly, front panel assembly,
Monitor/Control Processor (MCP) and Comtech EF Data SSPA modules. The amplifier is designed
using a Comtech EF Data low-loss combining technique and an MCP based temperature versus
gain compensation. Functional Block Diagrams for each unit are provided in this section:
Figure Description
Figure 1-2 CPA-050 Functional Block Diagram
Figure 1-3 CPA-100 Functional Block Diagram
Figure 1-4 CPA-175/CPA-200 Functional Block Diagram
Each CPA chassis consists of a power supply, fan assembly, front panel assembly,
monitor/control processor (MCP), and a Comtech EF Data SSPA module. The CPA is designed
using a Comtech EF Data low loss combining technique and an MCP based temperature versus
gain compensation.
Each CPA ISSPA is constructed with highly reliable Gallium Arsenide Field Effect Transistors
(GaAs FETs). With Third-Order Intermodulation products from 4 to 6 dB better than TWT ratings,
the Comtech EF Data unit replaces TWTs with saturated power levels of up to 400 Watts. These
CPAs also provide a Mean Time Between Failure (MTBF) that is 5 to 6 times greater than the
typical TWT MTBFs.
An AC power connector and On/Off switch are located on the chassis rear panel. A six-foot AC
power cord is supplied with the unit. Connectors for the external interface connections are
located on the rear of the CPA chassis.
Two exhaust fans are installed internally in the chassis for cooling. Cool air is taken in through
the front panel and exhausted out the rear panel.
All operator controls, indicators, and displays for local and remote operation are located on the
front panel of the CPA. The front panel features:
• A Liquid Crystal Diode (LCD) menu display, displaying two lines of 20 characters each.
• A six-button cursor array, used for setting or changing operating parameters.
• Six Light-Emitting Diodes (LEDs), providing quick reference to binary status points.
• –20 dBc Input and –40 dBc output sample ports, providing easy test point access.
The CPA remote control interface is selectable between EIA-232 and EIA-485, as well as full
Ethernet including Telnet, SNMP and pre-loaded Web Server Interface. All configuration control,
status retrieval, and adjustments are available locally through the front panel menu, or remotely
as simple ASCII commands through the serial interface. As a cost option, the remote control