Transformation of the Electromagnetic Field in an UWB Array of TEM Horns

Infinite ultra-wideband (UWB) arrays of TEM horns are considered. At the first stage, we calculate the array scattering parameters in quasi-periodical operating mode using Floquet channel model. The model is actualized in the HFSS electromagnetic simulation system. At the second stage, using calculated scattering matrix of the Floquet channel, we determine parameters of the array in the cluster excitation mode, including the field distribution in its emitting aperture. Two clusters are analyzed, finite in one coordinate and infinite in the other one. It is investigated how the cluster size, frequency, scanning in the sector of angles affect the shape of the amplitude-phase distribution of the field in the array aperture. It is shown that the distribution of the field in the emitting aperture can differ significantly from the distribution of exciting waves at the inputs of the array elements. It has been established that the field distortion due to its transformation inside the UWB array is an important factor that should be taken into account when designing an array. An explanation of this effect, based on the representation of the array field as a superposition of its eigenwaves is proposed.