Millimeter wave design of new two-imbricated-slot antennas for increasing the bandwidth at Ka band

A novel millimeter wave coplanar waveguide (CPW) fed slot antenna are introduced. Two configurations are proposed: simple and double bow-tie shaped slot antennas. The coupling from the coplanar line to the slot radiating element is performed via an aperture placed in the ground plane to which the coplanar line is connected. These novel configurations can be used as a radiating element in array antenna systems. These antennas have been developed to operate at a center frequency of 38 GHz (Ka band). The aim is to widen the bandwidth of the CPW fed patch antenna by using a slot instead of a patch as a radiating element. Simulation results of the return loss and the radiation patterns are presented and discussed. Impedance bandwidths (return loss < -10 dB) of about 9.2% and 15.13% are achieved for, respectively, the simple bow-tie and the double bow-tie configurations.