Atomic 2D electric field imaging of a Yagi–Uda antenna near-field using a portable Rydberg-atom probe and measurement instrument

We present electric field measurements and imaging of a Yagi–Uda antenna near-field using a Rydberg atom–based radio frequency electric field measurement instrument. The instrument uses electromagnetically induced transparency with Rydberg states of cesium atoms in a room-temperature vapor and off-resonant RF-field–induced Rydberg-level shifts for optical SI-traceable measurements of RF electric fields over a wide amplitude and frequency range. The electric field along the antenna boresight is measured using the atomic probe at a spatial resolution of <m:math xmlns:m="http://www.w3.org/1998/Math/MathML"><m:mrow><m:mrow><m:mrow><m:msub><m:mi>λ</m:mi><m:mrow><m:mi>R</m:mi><m:mi>F</m:mi></m:mrow></m:msub></m:mrow><m:mo>/</m:mo><m:mn>2</m:mn></m:mrow></m:mrow></m:math> λ RF/2 with electric field measurement uncertainties below 5.5%, an improvement to RF measurement uncertainties provided by existing antenna standards.