  Recently atomic based MW electrometry is experimentally demonstrated and
interferometry has been proposed. The proposed interferometry bypasses the
conventional, electrical circuit based MW interferometry in much superior
fashion. However, this scheme requires three different references for
characterizing the unknown MW field. In this work we theoretically study a
scheme to develop an atomic based MW interferometry having only one referenced
MW field. This scheme involves magnetic sublevels in the Rydberg states and
hence will be suitable in even isotope of Yb or alkaline earth element where
there is no complicacy due to absence of the hyperfine levels. Further, the
wavelengths to excite the Rydberg states, are very close and hence cancels the
Doppler shift more effectively which increases the amplitude sensitivity. We
characterize this system for the phase and the amplitude of the unknown MW
field w.r.t to the known field and compare it to the previously studied
systems.
