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dc.contributor.authorBeachem, Thomas Andrewen_US
dc.date.accessioned2014-03-14T21:49:48Z
dc.date.available2014-03-14T21:49:48Z
dc.date.issued1986-05-05en_US
dc.identifier.otheretd-11152013-040426en_US
dc.identifier.urihttp://hdl.handle.net/10919/45745
dc.description.abstractTWTAs (Traveling Xhuna Tube Amplifiers) are presently the primary life-limiting element of a communications satellite transponder. Satellite operators rely on spare ‘TWTAs to ensure that most of the transponders will be operating at the spacecraft end·of-life. We wish to track the °health° of the operating TWTAs in order to accurately predict the remaining useful lifetime of the satellite transponder. This information is very useful for system planning and risk assessment. The primary failure mechanism of a TWTA is cathode deactivation, symptoms of which are measurable from an earth station. Present testing methods require the interruption of the communications traffic signal, which leads to a loss in revenue generated by the satellite. We present new methods to test TWTAs without significant interference to the communications signal. These methods include the use of test—tone signals and spread spectrum techniques. The test—tone method is readily implemented using commercially available hardware. The spread·spectrum technique requires customized hardware, and so is more expensive. Finally, the data from these tests can be inserted into a transponder reliability model. The model is then used to predict the availability of the satellite transponder, up to and including the end-ef-life of the satellite.en_US
dc.format.mediumBTDen_US
dc.publisherVirginia Techen_US
dc.relation.haspartLD5655.V855_1986.B423.pdfen_US
dc.subjectTransponders.en_US
dc.subject.lccLD5655.V855 1986.B423en_US
dc.titleIn-orbit testing of satellite TWTA's without commercial traffic interferenceen_US
dc.typeThesisen_US
dc.contributor.departmentElectrical Engineeringen_US
dc.description.degreeMaster of Scienceen_US
thesis.degree.nameMaster of Scienceen_US
thesis.degree.levelmastersen_US
thesis.degree.grantorVirginia Polytechnic Institute and State Universityen_US
thesis.degree.disciplineElectrical Engineeringen_US
dc.contributor.committeechairBostian, Charles W.en_US
dc.contributor.committeememberPratt, T.en_US
dc.contributor.committeememberHa, Tri T.en_US
dc.identifier.sourceurlhttp://scholar.lib.vt.edu/theses/available/etd-11152013-040426/en_US
dc.date.sdate2013-11-15en_US
dc.date.rdate2013-11-15
dc.date.adate2013-11-15en_US


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