The properties of the longitudinal slot-pair on opposite wide walls of a rectangular waveguide are analysed. The general formulas used to find the solution of scattering fields are derived

and the equivalent parameters may thus be found as well. In the X-band

the resonant conductance and the resonant length of the slot-pair as a function of frequency and slot displacement from waveguide center line

together with the resonant length as a function of wall thickness are calculated.