V-band high efficiency corporate-fed 8 78 slot array antenna with ETSI class II radiation pattern based on gap technology

A multilayer gap waveguide 8 78 slot array antenna with high efficiency for 60 GHz applications is presented in this paper. The proposed antenna is composed of three unconnected metal layers. A ridge gap waveguide corporate distribution network feeds a radiation layer with 4 74 cavity-backed slot subarrays. The co-polar radiation pattern and sidelobe levels of the antenna are improved by using a simple slot-tilting method to fulfill the radiation pattern requirement of the ETSI 302 standard for fixed radio links. The fabricated prototype has a relative bandwidth of 12 % with input reflection coefficient better than -10 dB. The E- and H-planes radiation patterns satisfy the ETSI class II co-polar sidelobe envelope over 57-65 GHz frequency band. The measured total aperture efficiency is better than 65% over the operating frequency band