Implementation of Millimeter Wave Antenna Arrays by Diffusion Bonding

The possibilities of hardware miniaturization and bandwidth enhancement at millimeter-wave frequencies are regarded with great interest, specially for the incoming 5G communication environment. However, conventional manufacturing techniques struggle to provide the accuracy and tolerances required in radiofrequency devices at this frequency. In this work, a W-band circularly polarized 16×16 antenna array with a corporate waveguide feeding network is presented. Diffusion bonding manufacturing technique has enabled a working prototype with satisfactory experimental results, namely a 5.6 % effective bandwidth at 90 GHz with efficiency over 50 % and axial ratio under 3 dB.