Influence of VSWR of radiation elements on sidelobe degradation of low sidelobe array antennas

The influence of the VSWR (voltage standing wave ratio) of radiation elements on the sidelobe degradation of low-sidelobe array antennas is analyzed by deriving straightforward expressions. It is found that the relationship between VSWR and sidelobe level can be expressed with simple equations which depend only on reflection levels at elements and excitation phase differences. These equations can be used to determine the maximum VSWR that can be tolerated to achieve a specified level of sidelobe degradation. One result was that /spl Gamma//sub o/ must be smaller than -18dB if the sidelobes are to be suppressed to the level of -20dB.<>