Programmable aperture antenna using monolithically integrated MEMS switches

This dissertation presents a novel approach to millimeter-wave beam steering based on a programmable aperture antenna utilizing monolithically integrated micro electromachanical systems (MEMS) switches. Reconfigurable antenna-filter-antenna (AFA) elements based on slot antennas and switchable resonators are developed and used as the building block of adaptive lens-arrays and reflectarrays. These elements achieve a two-bit phase-shift function by switching between four bandpass modes of operation with 3-pole/4-pole frequency response. The methodologies for design, modeling, and miniaturization of the reconfigurable AFA are developed. The utility of this approach is demonstrated through fixed and programmable prototypes in lens-array and reflectarray configurations. The experimental results from fixed prototypes show an exceptional scanning performance that validates the underlying theory and design methodology. A fully integrated device comprising 484 AFA elements and 2420 RF MEMS switches is fabricated on a stack of two 4" quartz wafers with the SU-8 adhesive bonding. The design and fabrication issues are investigated and the measured data related to yield, frequency response and radiation performance of this lens-array are presented. Measured results show the feasibility of monolithic integration in large scale, and demonstrate a wide-angle beams-steering function in spite of the modest yield. Reflectarray designs are developed and their performance is verified by fixed prototypes. These experiments show the versatility of the reflectarray approach in achieving full two-dimensional scan and dual polarized operation. A bistatic reflectance model based on hybrid FEM/circuit simulations is developed to predict the radiation performance and scan blindness effects. The accuracy of model is verified by careful measurements.