Mutual impedance between two resonant-slot radiators

The paper presents investigations on the mutual impedance between two slots placed in close proximity. An analytical expression for the mutual impedance between two parallel longitudinal resonant slots in the broad wall of a rectangular waveguide is derived from the reaction of the magnetic field due to one of the slots, with the magnetic current exciting the other slot and with discontinuities in modal currents due to the two slots. The method of analysis is of general applicability. In the case under investigation, both slots are active, and a method for the experimental determination of mutual impedance between two active slots is presented. The values of mutual impedance computed from the theoretical formula are in good agreement with those obtained experimentally.