A K-band planar slot array antenna on a single layer ridge gap waveguide

A K-band slot array antenna is developed by using ridge gap waveguide technology in a single layer metal structure. A power divider of 1:4 is used to feed the ridge gap waveguide and the slots. The power divided itself is fed with a waveguide transition. Detail design of the antenna is presented. The antenna has the impedance bandwidth of 9% at the center frequency of 38.5 GHz, The antenna gain is 21 dBi and the side lobe level is less than 12 dB.