SRC-127

Microwave Power Transmission Technologies for Solar Power Satellites, Proceedings of the IEEE 101(6), June 2013, p.1442 section E.

Commissioned by IEEE. Who paid for a study is recorded because it bears on how its conclusions should be read, not because it makes them wrong.

Published claims resting on this source

• CLM-0111 An authoritative 2013 review says the 230 watt per square metre figure was chosen early in the design as a cautious maximum. It does not describe it as a measured or derived limit.
• CLM-0112 The same review says modern work finds about 1 kilowatt per square metre acceptable at 5.8 gigahertz, more than four times the older figure, and that commercial designs assume it.
• CLM-0113 As of 2013 the experiment needed to check these predictions had still not been done.
• CLM-0128 A 2013 review gives three references for the 1 kilowatt per square metre figure: two Japanese papers from 1995 and 1996, and a 1981 paper by Perkins and Goldman.
• CLM-0133 A 2013 review paper says calculations suggest a stronger microwave beam than the usual safety limit would still be fine at a higher frequency, but the paper itself says these predictions still need to be fully checked in space experiments.
• CLM-1467 (low confidence) Keeping people out of the area where the beam is strong is a plausible way for a strong beam to meet the 2020 international limit for public exposure, and international exposure guidance accepts limiting access as a way to comply. Other designs have worked this out: a 2013 Japanese review plans a no-entry area 3.5 kilometres across, and a 2007 international study sizes a 4-kilometre receiver this way. A 1977 US study set aside 204 square kilometres for one receiving site, without saying in its cost table what fixed that size, and costed buying and preparing that land. A 2026 international radio report that takes CASSIOPeiA as its example says the beam can be designed to fall below the public limit at the edge of the receiving site, with a safety zone matching the beam's footprint, about 3.5 to 6.5 by 7 to 13 kilometres in the UK. A diagram in it shows the receiving site taking 245 watts per square metre, but the report gives no figure for the beam's strength at the edge and no cost for the zone. A 2021 UK cost model for a CASSIOPeiA design includes the land for the receiving site but names no safety zone.

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