Sub-TeraHertz Modular Array Layout Optimization under Fabrication Constraints

Millimeter wave (mmWave) and sub-TeraHertz (sub-THz) multi-user multiple-input multiple-output (MUMIMO) communications operating in the frequency spectrum (30-300 GHz) have already been identified as the most promising candidate for the second phase of 5G and Beyond (5GB) wireless systems aiming to achieve broadband data communications at rates higher than 1 Gb/s while operating in very dense urban small-cell environments. Due to the presence of strong isotropic pathloss in mmWave/sub-THz frequencies, high antenna gains realized through large antenna arrays will be required to mitigate these effects. The small wavelengths under which mmWave and s-THz systems operate, allow for integration of more compact antenna elements. However, the fabrication of such antennas poses challenges such as positioning tolerance. In this work, we introduce a novel modular array synthesis approach and further investigate the effect of non-ideal element/module positions within an array and provide an optimization framework to minimize the expected synthesized array pattern error taking positioning tolerances into account. Furthermore, we use the realized element pattern of the proposed D-Band patch element with an RF bandwidth of over 10 GHz to demonstrate the results of the proposed optimization algorithm.