PAGE CONTENTS
Objectives
The strategic and commercial objective for this development is targeted frequency converter equipment for GEO Mobile systems for L & S-band On-board Digital Beam-forming systems. Such system typical have 130-150 frequency converters between the antenna and the DSP. The frequency converters are often named Pre-processors and Post-processors.
In the program one EQM combining the Pre and Post Processor has been designed, developed and successfully qualified.
In addition to the performance and technological challenges in the program, a major task for this program has been also to develop an organization tailored to the industrial activity. The challenge is to be able to handle a large HW quantity needed for such programs in an efficient way within short time periods
Challenges
The key issue in this program has been the design, development and qualification of an EQM suitable for pre & post processing (frequency conversion) for digital beam forming L-& S-band mobile services satellites.
Design Challenges
The design challenges is to perform frequency conversion and filtering in multiple channels without jeopardizing the antenna element phase tracking.
Industrial Organization
In addition to the design challenges, there has been a challenge to prepare an industrial organization able to develop, manufacture and test a large amount of critical hardware in a short time period.
System Architecture
The Pre-Processor provides frequency conversion of the L-band uplink frequency down to IF, while the Post-Processor provides frequency conversion from IF up to the L-band downlink frequency. Each processor unit contains 20 identical frequency converter chains of which 16 are active. The converter chain includes channel filtering by means of SAW filter and individual gain setting via tele-command.
The Pre- and Post-Processors make part of a beam forming system thus, in addition to frequency conversion and channelization parameters, critical performance parameters are gain and phase tracking both between the internal converter chains and between the converter types.
Both processors employ spectral inversion and the internal LO frequencies are generated as an integer multiple of the input MRO signal (around 10MHz).
The Pre- and Post-Processor assemblies are very similar units even though one provides frequency up-conversion while the other provides down-conversion. The two converter units thus opens for a high degree of reuse with respect to designs, parts and even slices. Key parts like hybrids, technologies and assemblies are common.
This has been a key element to provide an efficient design that is suited for manufacturing of a large amount of critical hardware in a short time period.
Plan
The following development plan has been followed during the program:
PDR – Preliminary Design Review
This milestone concluded the initial work with the unit optimization and critical design
CDR– Critical Design Review
This milestone concluded the detailed design and development as well as the supporting performance and reliability analysis.
EQM TRB – Test Review Board / Final Review
After the completion of the EQM test campaign, the TRB was successfully held.
Current Status
The program is now completed.
Through the Kongsberg Norspace has designed, developed and successfully qualified an EQM suitable for pre & post processing of digital beam forming L- & S- band mobile services satellites. Such processors typically consist of 130-150 frequency converters, thus a significant effort has been put into the preparations to ensure a cost effective industrial implementation.
