Partnering with Universities on Project AETHER

Over the past two decades the frequency bands that flight test ranges use to stream data off an aircraft have been sold, traded, and pushed aside to make room for commercial wireless, and every one of those moves has forced the ranges to replace hardware on the ground.

The reason it recurs sits in the physics of how a radio receiver works. An antenna is a piece of metal sized to the wave it is meant to catch, and the filter and amplifier sitting behind it are built for that same band. Move the band and the metal is wrong. The receiver is not a general purpose instrument that happens to be tuned. It is a purpose built object, and the purpose was set by a regulatory decision that can be reversed.

There is another way to detect a radio wave, and it involves no metal at all.

Take a small glass cell filled with cesium vapor. Shine two lasers through it, tuned so that the outermost electron of each atom is lifted into an enormous orbit, hundreds of times wider than the atom's ordinary size. Physicists call an atom in that condition a Rydberg atom. The electron is now loosely held and very far from home, which makes it acutely responsive to any electric field passing through the cell. A radio wave is an electric field.

When the wave arrives it disturbs those inflated atoms, and the disturbance changes how much laser light reaches a photodetector on the far side of the cell. The measurement is therefore optical. You point a laser at a glass cell, watch the brightness change, and what you are actually reading is radio.

The tuning knob becomes a laser rather than a piece of metal. Which frequency the cell listens to depends on which orbit the electron has been parked in, and that is set by where you put the laser. One physical sensor can be pointed at frequencies that would otherwise demand separate hardware, and a reallocation becomes a software and optics problem.

Calibration changes as well. The strength of the field follows from properties of the atom itself, quantities that are the same in Atlanta as at Edwards and the same a decade from now as today. The sensor checks itself against nature instead of against a reference antenna that somebody else had to calibrate first.

Now the other side of the ledger, because a claim like this is only worth reading if the costs arrive alongside the benefits. An ensemble of atoms takes time to settle into a new state, and that settling time is slower than an electronic circuit, which puts a ceiling on how fast information can come through. Telemetry runs at megabits per second. Whether the atoms can keep pace is not a detail to be sorted out later.

Project AETHER is a twelve month study built to answer it. We construct the conventional receiver in simulation, construct the atomic one beside it, drive both with the same waveforms through the same modeled multipath conditions, and report where the quantum front end wins and where it does not.