Low-cost integrated waveguide antenna front-end solutions for fifth generation cellular systems and beyond

At mm-wave frequency, SIW (substrate integrated waveguide) is an emerging outstanding candidate to implement low loss and low cost feeding networks. SIW-fed antenna is able to yield high radiation efficiency and broadband impedance behavior. In this thesis, SIW feeding transmission technology is chosen to implement power and phase distributing networks for realizing high efficiency antenna front ends.;The main scientific and technical contributions can be summarized into two parts. In the first part, solutions for efficiently radiating apertures have been proposed such as high gain linear polarization (LP) antenna arrays, pencil beam antenna arrays, dual linear polarization (DLP) antenna arrays and dual circular polarization (DCP) antenna arrays. The radiating element choice with excellent radiation characteristics is vital in realising high gain antenna array and electronically steerable phased arrays. In the second part, new techniques have been proposed to steer the fixed beam into multiple directions in elevation and azimuth utilizing passive phase shifting network.;At 60 GHz frequency, dielectric rod antenna is selected for linearly polarized radiation and cavity backed metallic circular patch antenna is selected to obtain circular polarization radiation. Single rod antenna element is experimentally characterized to validate the proposed concept. In the next stage, high gain antenna array with 45° linear polarization utilizing rod antenna radiating element is demonstrated and feeding implemented in three dimensional (3-D) architecture is integrated along with the 4 x 4 antenna array. The data handling capability of single polarization antenna array is increased up to two fold by integrating two orthogonal polarized antenna arrays with an aperture area of one single polarized array. The Rod antenna application is also extended to obtain phase steered beams in horizontal plane in a planar 1-D phased array antenna configuration. The demonstrated 1-D scan phased array is simple to manufacture but the scanned patterns exists only in horizontal plane.;The Butler matrix BFN is modified and integrated under the 2 x 2 patch array, resulting LP scanned pattern in elevation and azimuth simultaneously. The Butler matrix is compact in size and feeding planar antenna array. The compact 2-D scan phased array is realized in multi-layer configuration and experimentally validated at Ka-band frequency range.;In the next technique, CP beam is steered in 2-D scans space. At 60 GHz frequency, circularly polarized radiated beam is obtained by feeding an array of patch antenna using SIW feeding topology. At first, CP antenna characteristics are obtained by inserting two notches on the outer circumference of a LP patch. In the next stage, 2 x 2 CP patch array occupying compact size and excellent axial ratio (AR) performance is realized in the SIW technology. The radiated beam with CP characteristics is phase steered in elevation and azimuth using three dimensionally constructed Butler matrix BFN. The two dimensional scan CP phased array antenna system is readily usable to implement antenna front end in a cognitive radio system.;The 2-D scan mechanisms utilizing phase and frequency scan simultaneously have been demonstrated in the work. In the first technique, a technique for achieving simultaneous multiple scanned directional beams limited scan region is introduced and its development is enabled by the substrate integrated waveguide (SIW) technology. The 2-D scanning is achieved by phase steering each beam of frequency scanned leaky wave array. Rotman lens based BFN and array of LWA sources are integrated on the output contour to realize the 2-D scan conformal phased array antenna.;In the last technique, full-space scanning 3-D phased array antenna is proposed to cover 320° scan region in azimuth and 20° scan region in elevation. Two-layered feed part is implemented by the combination of 90° H-plane coupler and two similar 4 x 4 Butler matrices. In this configuration, one of the beams can be used for transmit operation while the other beam can be used for receive operation simultaneously. Measured S-parameters and directional pattern measurements have confirmed the multi-dimensional scanning capability of the proposed MBA. In the final stage, the beam scanning range is further extended to cover the full-plane region by placing two independent MBAs orthogonal to each other. The proposed technique is scalable for various system applications up to W-band frequency range and beyond.;In this PhD thesis, complete set of antenna front-end solutions are proposed and validated in a low-cost integrated waveguide technology for future 5 th generation cellular communication. The antenna radiating part is designed and simulated in full-wave electromagnetic software Ansoft high simulation software (HFSS) and experimentally verified in far-field MI technology anechoic chamber. The results presented in this PhD thesis are published in US patents (pending), reputed international journals and also presented in international conferences held in North America, Europe and Asia-Pacific regions. (Abstract shortened by UMI.).