  On-resonance Rydberg atom-based radio-frequency (RF) electric field sensing
methods remain limited by the narrow frequency signal detection bands available
by resonant transitions. The use of an additional RF tuner field to dress or
shift a target Rydberg state can be used to return a detuned signal field to
resonance and thus dramatically extend the frequency range available for
resonant sensing. Here we investigate three distinct tuning level schemes based
on adjacent Rydberg transitions, which are shown to have distinct
characteristics and can be controlled with mechanisms based on the tuning field
frequency or field strength. We further show that a two-photon Raman feature
can be used as an effective tuning mechanism separate from conventional
Autler-Townes splitting. We compare our tuning schemes to AC Stark effect-based
broadband RF field sensing and show that although the sensitivity is diminished
as we tune away from a resonant state, it nevertheless can be used in
configurations where there is a low density of Rydberg states, which would
result in a weak AC Stark effect.
