Most of the transmitarray phase shifting cell
designs assume a periodic repetition of the same cell to account
for the coupling effects of the neighboring cells. However the
behavior in terms of magnitude and phase of the transmission
coefficient calculated in this way may change when the
neighboring cells have different phase, as normally happens in
transmitarrays due to phase discretization. This paper
characterizes this effect using a family of sub-wavelength patch
cells covering the entire 360º phase shift interval, all with
transmission coefficient better than -0.2 dB in the periodic
structure. A stepped-phase structure is analysed considering
different phase step values from 5º up to 90º. It is shown that the
magnitude of the cells transmission factor changes considerably
at the transition between different elements, with the unit cells
with higher phase shift showing increased transmission while the
lower phase shift cells in the transition tend to block the
transmission more.