High Gain Metal-Only Reflectarray Antenna Composed of Multiple Rectangular Grooves

Abstract

Using an overlapping T-block method based on mode-matching technique and virtual current cancellation, the scattering formulations for a metal-only reflectarray antenna composed of multiple rectangular grooves are rigorously presented in fast convergent integrals. By matching the normal boundary conditions at boundaries, we get the simultaneous equations of the TE and TM modal coefficients for plane-wave incidence and Hertzian dipole excitation. A metallic-rectangular-grooves based reflectarray fed by a pyramidal horn antenna was fabricated and measured with near-field scanning, thus resulting in 42.3 [dB] antenna gain at f = 75 [GHz]. Our circular reflectarray has 30 [cm] diameter and 5 961 rectangular grooves on its metal surface. The simultaneous equations for a Hertzian dipole feed are solved to approximately obtain the radiation characteristics of a fabricated reflectarray. The measured results are compared with those of the overlapping T-block method and the FDTD simulation and they show favorable agreements in terms of radiation patterns and antenna gain.