Recent developments in solid state power amplifier technology and their applicability to third generation mobile space segment systems

It is anticipated that INMARSAT's third generation mobile satellite system will be typified by the necessity to provide for a continuation of global communications whilst simultaneously meeting the requirements for communications to a large number of smaller mobile Earth stations on a regional basis. ESA's ARAMIS project has covered considerable ground in assessing payload configurations to provide at least one example of such a multimission mobile satellite service. Emerging from that study was the criticability of a number of functional areas but in particular the L-band power amplifier. A number of active multiple-beam phased array systems are examined and each assessed in terms of the requirements of the distributed high power L-band power amplifier subsystem. Various classes of power amplifier design are discussed and a novel quasilinear design described which has very specific applications in phased array systems up to S-band.<
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