Recently, gap waveguide technology is introduced as a promising guiding structure for millimeter-wave systems. The conception of gap waveguide technology can be modeled for theoretical analysis by two parallel plates, a top perfect electric conductor layer and a bottom perfect magnetic conductor layer. This structure stops all modes propagating in all directions except for a quasi-TEM mode along the strip over a specic frequency band (stopband) when the gap between PEC and PMC plates is smaller than quarter wavelength at an operation frequency. Until now there are already four dierent versions of this novel conceptgroove, ridge, inverted microstrip and microstrip ridge gap waveguides. The proposed thesis mainly focuses on array antenna design based on gap waveguide technology. We present several low-prole single-layered and multilayer corporate-fed slot array antennas with high gain for the 60-GHz band and 140-GHz. The aim of this thesis is to demonstrate the advantages of gap waveguide technology as an alternative to the traditional lowloss waveguide structure to overcome the problem of good electrical contact due to mechanical assembly. Measurement results and experimental validation are provided for the presented antenna design