A broadband microstrip reflectarray using sub-wavelength patch elements

In this paper we report on a broad band reflectarray antenna using sub- wavelength elements based on variable size patch element analysis. Two Ka-band reflectarrays using single layer variable patch sizes as phasing elements have been developed. One is designed with the conventional lambda/2 element spacing and the other one with lambda/3 element spacing. Although both antennas demonstrate good performance, the one using sub-wavelength elements achieves a wider bandwidth.