Value chain · CLM-1122
In plain terms
About twenty thousand postage-stamp-sized antenna-plus-diode cells, each with an off-the-shelf microwave diode, wired into tiles, then panels a metre square, then four panels side by side: a bit over four square metres in all.
The claim as recorded
The NRL 2022 X-band rectenna array is built from a microstrip patch element on a "0.51-mm Rogers 3003 substrate" with 18 um copper, one "MACOM MA4E1317 Schottky diode" (a commercial GaAs diode), "impedance matching and harmonic tuning at 9.7-GHz as well as the 2nd and 3rd" harmonics and "A 2-pF capacitor" to "filter out any RF power not reflected by the harmonic stubs"; a tile has "12 rows of 17 rectenna elements whose DC outputs connect in parallel on a lower substrate layer" with the 12 rows in series, and a "181 mm x 256 mm", "203-element tile"; "4 rows of 6 parallel-connected tiles combine in series to form a 1.02 m x 1.09 m rectenna quadrant" of 24 tiles under a 25.4 mm polyurethane foam radome, "each quadrant contains 4872 diodes"; "Four quadrants are connected in parallel" to make the array, so 19,488 elements on about 4.45 m2 at a 15.1 mm (0.49 wavelength) square pitch.
Evidence behind this: T1-peer-reviewed description of the hardware as built for a measured demonstration; the counts are the authors' and the lattice arithmetic is this record's.
Scope and limits
12 rows of 17 is 204 positions against the 203 elements the paper states twice and its 4,872 diode count confirms: an in-source inconsistency, recorded here as a suspected typesetting or counting slip in the paper and not decided; this record carries 203. At a zoom-10 crop the Fig. 4b photograph shows 12 rows of 17 positions with one bottom-row position carrying a light label rather than a dark patch, which may be the position that is not an element; a photograph reading only, not a statement of the paper. The element count, pitch and 4.45 m2 are arithmetic on the stated dimensions; the paper's own area statements are "4 m2" (abstract, conclusion) and 4.49 m2 (Table 2). The 18 um copper and the lower-layer DC bus are stated without drawings of the DC network.
What it assumes
One diode per element (the element description and the diode count agree on it).
Where it comes from
PDF 2 / printed 29: "0.51-mm Rogers 3003 substrate" (read at the render; the text layer drops the line-end hyphen); "MACOM MA4E1317 Schottky diode" (normalised); "impedance matching and harmonic tuning at 9.7-GHz as well as the 2nd and 3rd" (normalised). PDF 3 / printed 30: a 2 pF capacitor is also included, the paper says, to filter out any RF power the harmonic stubs do not reflect (R1); "Each tile has 12 rows of 17 rectenna elements whose DC outputs connect in parallel on a lower substrate layer" (normalised); "12 of these rows connect in series to form the 181 mm" (normalised); "203-element tile" (raw); the Fig. 4 caption has the DC output of 203 rectenna elements combining to form a 181 mm x 256 mm tile (normalised); "4 rows of 6 parallel-connected tiles combine in series to form a 1.02 m x 1.09 m rectenna quadrant" (normalised); Fig. 5 caption "24 rectenna tiles being assembled into a quadrant" (raw); "25.4-mm-thick extruded polyurethane foam" (raw); "Four quadrants are connected in parallel" (normalised). PDF 10 / printed 37: "each quadrant contains 4872 diodes" (raw). Recomputed: 24 x 203 = 4,872; 4 x 4,872 = 19,488; 6 x 0.181 = 1.086 m and 4 x 0.256 = 1.024 m (the quadrant); 4 x 1.02 x 1.09 = 4.45 m2; 256 / 17 = 15.06 mm and 181 / 12 = 15.08 mm; lambda at 9.7 GHz = 30.9 mm, 15.1 / 30.9 = 0.49; 1.112 m2 / 4,872 = 2.28 cm2 per element.
Basis: mm; m; element and diode counts; m2
Cite this
energyaperture.com/c/clm-1122
CLM-1122, Energy Aperture, as of 2022-01.
Connected records
Other published records linked to this one. A list, not a judgement.
- Also from SRC-270
- CLM-1123A five-metre dish and a 100 kW radar-type pulsed tube a kilometre away, bounced partly off the ground on purpose to get more power onto the...CLM-1124One panel the size of a sheet of paper turned about seven-tenths of the microwave power landing on it into DC, and did best at about three...CLM-1125Four square metres of receiver turned 73 per cent of the microwave power arriving at it into 1.65 kW of DC, measured a kilometre from the...CLM-1126They deliberately fried each of the four panels with ever-stronger pulses. A bare panel gave up at 672 watts out; clamping its voltage with...CLM-1127As flown, under two per cent of the microwave power fed to the dish came out of the receiver as electricity, because the beam had to be...CLM-1128A second test used a big radar dish in Massachusetts to light up a strip of LEDs on a tower over a kilometre away, with about a kilowatt...CLM-1129The authors say the 1975 record still stands at twenty times their power, that the custom diodes which set it no longer exist, and that...CLM-1130A quick way to size a ground-to-ground beam: at the distance where the dish stops focusing, the cone holding half the power is about twice...More on the source page.