Value chain · CLM-1144
In plain terms
In 2019 the same Japanese array put four kilowatts per square metre onto a paperback-sized rectenna under a hovering drone ten metres up, giving about 60 watts, not enough to fly it but enough to stretch the battery.
The claim as recorded
In May 2019 the third METI experiment beamed power from the 2015 phased array to a flying drone carrying "a new small and lightweight rectenna whose size was 200 mm" x "186 mm with 17 circular microstrip antennas": "The microwave power density was 4 kW/m2 at the drone at a distance of 10 m. The DC output power was approximately 60 W. The drone could also receive approximately 42 W at 30 m", which was "insufficient to fly the drone without the battery" but extended its flight time.
Evidence behind this: T2-review restatement of Mihara et al. IAC 2017 [100] and the rectenna paper [101], not held.
Scope and limits
4 kW/m2 IS THE HIGHEST STATED WORKING DENSITY IN THE REVIEW, TEN TIMES SHARP'S 400 W/m2 AND FOUR HUNDRED TIMES THE ICNIRP 10 W/m2 PUBLIC LIMIT - it is a drone-borne receiver at 10 m, not a ground exposure. The 40 per cent is this record's arithmetic. Primaries not held.
What it assumes
The 4 kW/m2 is the density over the rectenna's face.
Where it comes from
PDF 11 / printed 239: "In May 2019, the third METI experiment successfully beamed power to a flying drone [100]" (R1); "This experiment reused the phased array showing in Fig. 21 and developed a new small and lightweight rectenna whose size was 200 mm" (normalised); "186 mm with 17 circular microstrip antennas [101]" (normalised); "The microwave power density was 4 kW/m2 at the drone at a distance of 10 m. The DC output power was approximately 60 W. The drone could also receive approximately 42 W at 30 m" (normalised); "Although this received power was insufficient to fly the drone without the battery, the beamed power was able to extend the battery life and therefore the drone flight time" (R1). Recomputed: 0.200 x 0.186 = 0.0372 m2; 4 kW/m2 x 0.0372 = 149 W incident; 60 / 149 = 40 per cent RF-to-DC at 10 m; 42 W at 30 m is 70 per cent of the 10 m output at three times the range.
Basis: kW/m2; W DC; m; mm; element count
Cite this
energyaperture.com/c/clm-1144
CLM-1144, Energy Aperture, as of 2021-01.
Connected records
Other published records linked to this one. A list, not a judgement.
- Also from SRC-269
- CLM-1134The field's own 2021 scorecard: the two records were both set in 1975 (30-35 kW across about a mile, and 54 per cent DC in to DC out at...CLM-1135Modern power beaming, by the review's dating, starts in 1963 with a radar tube, a horn five and a half metres away and a single vacuum-tube...CLM-1136The famous 1964 helicopter hung fifteen metres up for ten hours on beamed microwaves, rectified by four and a half thousand diodes; then...CLM-1137In 1987 a Canadian model plane with a four-and-a-half-metre wingspan flew for twenty minutes at 150 metres on nothing but a microwave beam...CLM-1138A 1994 Japanese test sent five kilowatts from a three-metre dish to an eleven-square-metre rectenna 42 metres away and caught about...CLM-1139A 1995 Japanese blimp carrying a three-by-three-metre rectenna flew for four minutes at fifty metres on ten kilowatts of microwaves from...CLM-1141In 2002 a metre-wide rectenna moved along an exhibition floor in Houston, tracked by a self-steering 5.8 GHz beam, converting 82 per cent...CLM-1142In 2015 Mitsubishi Heavy sent ten kilowatts of microwaves half a kilometre along a Kobe pier to an eight-by-eight-metre receiver, enough to...More on the source page.