RF stands for radio frequency, and its radiation is a "nonionizing electromagnetic energy characterized by relatively long wavelength, low frequency, and low photon energy," according to the division of Environment, Health and Safety at Berkeley Lab. Microwave radiation is considered a subset of RF radiation. Radiofrequency energy includes radio waves and microwaves. If microwaves were used, the technology is not rare, and more than one country could be using it. The statement goes on to say "...this weapon is designed to bathe a target's living quarters in microwaves."
The three countries mentioned have no nuclear secrets.
( z0 have :ARG0 ( z1 country :quant 3 :ARG1-of ( z2 mention ) ) :ARG1 ( z3 secret :mod ( z4 nucleus ) ) :polarity - )
(z0 / have-03
    :ARG0 (z1 / country
              :quant 3
              :ARG1-of (z2 / mention-01))
    :ARG1 (z3 / secret
              :mod (z4 / nucleus))
    :polarity -)
The three countries mentioned have no nuclear secrets .
z1 :quant 1
z1 :ARG1-of z2
z0 :ARG0 z1
z0 :polarity 0
z3 :mod z4
z0 :ARG1 z3