Rydberg atom receivers have the potential to supplement or replace traditional sensing technologies due to the high sensitivity, electrically small packaging, and unconventional field detection mechanisms they can provide. Given the importance of angle of arrival (AoA) estimation for geolocation and the potential impact of these technologies, more work is needed to understand the Rydberg sensor’s impact on AoA estimation. While there have been many experimental and theoretical efforts to improve the sensitivity and bandwidth of these quantum sensors, few papers have explored the impact these technologies will have on AoA estimation. This paper presents a numerical study of AoA estimation using a simulated linear array of Rydberg atom receivers consisting of vapor cells with laser-defined sense volumes. By utilizing atomic physics and electromagnetics simulations, it is shown that uncompensated atomic transient effects and RF dispersion in glass vapor cell arrays can substantially degrade AoA estimation when compared with a traditional dipole array.

This paper describes integration of a software defined antenna (SDA) and a software defined radio (SDR) to enable dynamic and automatic selection of physical propagation channels. The SDA, an agile aperture antenna (A3), provides monolithic microdiversity, i.e. multiple antenna states within a single structure and within a space having maximum dimension of approximately one wavelength. In this way physical channel selection occurs outside, and therefore augmenting, the front-end electronics. The independent controllable parameters for channel access include: frequency, polarization (full Poincaré sphere), and pattern (in two dimensions). Several different tests were conducted to maximize a quality figure of merit calculated by the radio. Both library-based and evolutionary search techniques were used, resulting in short term channel improvements on the order of 10 dB, and long term fully optimized improvements on the order of 20 dB.