Wideband Sub-terahertz Coplanar Waveguide-Fed Spiral Antenna

This paper presents the design, simulation and characterization results of a wideband sub-terahertz membrane supported coplanar waveguide fed Archimedean spiral antenna. A fully parameterized 3D electromagnetic model was developed and a parametric study up to 350 GHz is performed. A 2 turns antenna placed over a metalized plate is optimized and the simulated results show vertical bar S11 vertical bar < -10 dB between 60 - 150 GHz, a directivity of 7-10 dBi and a simulated efficiency larger than 60% between 70 - 150 GHz. The measured results showed good matching from 75 - 110 GHz, in good agreement with simulations, a measured antenna gain of 10.6 dBi at 94 GHz and a broadside axial ratio smaller than 3 dB between 77 - 97 GHz. With an compact membrane area of 5.3 x 5.3mm(2) the performances of the proposed antenna are beyond the previously reported CPW fed spiral antennas.