Development of a center fed slot array antenna with very low side lobes using ridge gap waveguide (RGW) technology

A center-fed slot array antenna based on ridge gap waveguide (RGW) technology is presented. In the proposed structure, no aperture blockage is introduced which provides easy control on side lobe level (SLL) especially for low values of below -20 dB. Furthermore, thanks to the compact nature of TEM-based RGW line in E-plane, the proposed structure, unlike its TE-based groove gap waveguide (GGW) counterpart does not suffer from the grating lobe problem when applied in a two-dimensional array. For proof of concept a 4x10 slot array based on the proposed RGW-based topology is designed and fabricated for operation at 15 GHz. Both simulation and measurement results show proper radiation performance including the gain of 20 dB and the SLL of -23 dB as well as the fixed beam over the antenna operating bandwidth.