RF conversion and phased arrays
Turning direct-current (DC) power into a microwave beam, forming and steering that beam, and how much of the power reaches the ground.
This area is studied in more depth than the rest of the value chain. It spans 2 layers, with 347 published records between them.
Where each layer stands
Transmitter and aperture: where it stands
No source in these records reports a test of a transmitter near full scale. The transmitter turns DC power into a microwave beam. A December 2024 Japanese aircraft test aimed a 5.8 GHz beam over about 5 km, but its preliminary report gave received signal levels only, with no transmitted power, DC output or efficiency (CLM-0294). A 2026 array reached a peak of 172 W/m2 on a 1 m2 receiver at 6.5 m (CLM-0512). The 1978 US design is said to spread its beam out if the pilot signal, sent up from the ground to show the satellite where to aim, stops. Peak intensity then falls from 23 to 0.003 mW/cm2. A 1981 programme summary says this takes milliseconds (CLM-0911, CLM-1020). A 2013 review says the 230 W/m2 limit was chosen early to avoid strong interaction with the ionosphere, one of at least four accounts of its origin that disagree (CLM-0111). The same review says about 1 kW/m2 may not be critical at 5.8 GHz, while other estimates are lower (CLM-0112).
The beam
A power satellite in geostationary orbit, the high orbit where a satellite stays over one point on Earth, cannot focus its beam to a point. Diffraction, the natural spreading of waves, spreads it over a patch kilometres wide (CLM-0889). Every source found that gives the design figure of 230 W/m2 at the centre of the receiving site traces it to one 1978 American report (CLM-0020, CLM-0044). The 1978 report itself says heating of the ionosphere, the electrically charged upper atmosphere, may limit the beam to about this level, a theoretical threshold (CLM-0039). Accounts of why the figure was chosen disagree (CLM-0111). No experiment has been found that tests that limit at the beam's frequency (CLM-0030). On the ground, power has been beamed over 1 to 2 km: 30 kW of DC by 1976 (CLM-1097), and 1.65 kW at the peak of short pulses in a 2022 US Navy test (CLM-1125). A 2024 test from a jet did not report any delivered power (CLM-0294).
Layers in this area
| Layer | Covers | Target | Reached | Records |
|---|---|---|---|---|
| VC05 Transmitter: DC to beam and aperture | DC to RF or DC to optical conversion, amplifiers, phase control, beam forming, transmit aperture | L3 | L3 | 106 |
| VC06 Beam link and propagation | Link budget, diffraction and beam geometry, atmospheric effects, pointing accuracy and safety, frequency choice and beam power density | L3 | L3 | 344 |
The record count is every record tagged to that layer, not the number published. What the depth levels mean.