Value chain · CLM-1250
In plain terms
In a 2015 ground test in Japan, a 1.8 kW microwave beam sent over 55 m delivered about a third of a kilowatt when the steering corrected a deliberate panel misalignment, and about 90 W, roughly a quarter of that, when it did not.
The claim as recorded
JAXA's page on the 2015-03-08 ground test at the Mitsubishi Electric facility in Hyogo, run with Japan Space Systems under METI's project, reports these results. About 1.8 kW was transmitted at 5.8 GHz over about 55 m. About 320 to 340 W was received with the beam-pointing control compensating a 30 mm offset between the upper and lower antenna panels, and about 85 to 95 W with the transmission phase not altered to offset it. JAXA built the beam-pointing-control subsystem, with a 2.45 GHz pilot signal; Japan Space Systems built the power transmitting and receiving subsystems.
Evidence behind this: T5, an agency web page reporting a test it took part in; it permits "JAXA reports Y for the 2015-03-08 test" only. No test report or method is held.
Scope and limits
Footnote *1 gives the 320 to 340 W as the power with the panel offset compensated, equivalent to no displacement; the p.3 diagram takes the reading on the DC side, before the DC 50 V to AC 100 V inverter. So the 320 to 340 W of 1.8 kW (about 18 to 19 per cent, our arithmetic) is neither an RF-to-DC nor a DC-to-DC efficiency as QST-026 asks. CLM-1143 (SRC-269) gives 335 W at 59 per cent and a stated 42 per cent total receive efficiency for the same test; the two sources are consistent on 1.8 kW, 55 m and the received power range. One test at 55 m; it says nothing of path loss over orbital distances. Read from an image-only print; the cookie banner hides text at page bottoms (see the transcript's GAPS).
What it assumes
No assumptions are recorded against this claim.
Where it comes from
text, PDF p.4, results table: transmit frequency 5.8 GHz; transmit power approx. 1.8 kW; receiving power approx. 320 - 340 W, with notes "*1" (equivalent to the power with no positional displacement between panels) and "*2" ("Approx. 85-95 W when the transmission phase is not electronically altered to offset the displacement"); transmission distance approx. 55 m. PDF p.3: date "10:15 to 16:45, March 8, 2015", site Mitsubishi Electric facility in Hyogo Prefecture; figure label "30-mm displacement between upper two panels and lower two panels" to simulate the deformation of a large antenna. PDF p.2: block diagram, R&D by JAXA the beam-pointing-control subsystem, by J-spacesystem the power subsystems; pilot signal 2.45 GHz band.
Related records
- Answers question
- QST-006 not published in this releaseQST-026 not published in this release
Cite this
energyaperture.com/c/clm-1250
CLM-1250, Energy Aperture, as of 2015-03-08.