  Radio frequency antennas based on Rydberg atoms can in principle reach
sensitivities beyond those of any conventional wire antenna, especially at
lower frequencies where very long wires are needed to accommodate the growing
wavelength. This paper presents a detailed theoretical investigation of Rydberg
antenna sensitivity, elucidating parameter regimes that could cumulatively lead
to 2--3 orders of magnitude sensitivity increase. Of special interest are
three-laser setups proposed to compensate for atom motion-induced Doppler
spreading. Such setups are in indeed shown to be advantageous, but only because
they restore sensitivity to the \emph{expected} Doppler-limited value, removing
significant additional off-resonance reductions.
