Synthetic Aperture RF Reception Using Rydberg Atoms

Rydberg atoms show great promise for use as self-calibrated electric field sensors for a broad range of frequencies. Their response is traceable to the international system of units making them a valuable tool for a variety of applications including traceable channel sounding. The Rydberg atom sensor is an electrically small point probe. Its detection volume is defined by the overlap of probing and coupling lasers, which can be as small as hundreds of microns. We present measurements of the beam-formed output of a horn antenna in the far field at 28 GHz. We move a Rydberg atom sensor over a synthetic aperture to obtain high angular resolution of the received signal and employ electromagnetic induced transparency with AC stark shifting and a local oscillator signal radiated onto the atoms for magnitude and phase detection at each location in the area. These results demonstrate the use of these Rydberg atom sensors in a synthetic aperture configuration and inform their eventual use for traceable channel sounding measurements.