Coplanar corporate feed effects in microstrip patch array design

The use of coplanar corporate feeds for microstrip patch arrays leads to constructional simplicity, but also to performance degradations due to feed radiation, in addition to limitations due to feed resistive loss, surface waves, mutual coupling and tolerances. These effects are quantified, and this allows specification of array performance limitations in addition to the recommendation of the use of smooth feed discontinuities, high line impedance, and thin substrates. Improvements due to the use of alternate feed geometries, such as sequentially rotated feeding and subarraying, are also quantified and are shown to be substantial.