The Shorted Annular Patch as a Global Navigation Satellite System Antenna (De Shorted Annular Patch als Global Navigation Satellite System antenne)

Today's growing industry of Global Navigation Satellite System (GNSS) demand higher performant antennas at lower cost. A special class of patch antenna referred to as reduced surface wave antennas turns out to be a valid candidate. Within this special class of patch antennas, especially the shorted annular patch is of high interest. This dissertation investigates the phenomenon of surface waves and presents easy to implement calculation strategies of quantities related to surface waves. The shorted annular patch as a special reduced surface wave patch antenna is thoroughly investigated. Simplified approximate calculation techniques of initial shorted annular patch dimensions prior to full wave simulation optimization are presented. Multipath is an important phenomenon in GNSS leading to position acquisition inaccuracies. Several ways of evaluating antenna performance with respect to multipath performance are outlined. The original shorted annular patch antenna multipath design optimum turns out to be inaccurate. A new design optimum based on the multipath research presented in this dissertation is determined. GNSS antennas are always accompanied with electronics such as filters and low noise amplifiers. Good electrical design implies proper electrical shielding. The effects of a close-by cylindrical electronics housing on radiation pattern characteristics of two shorted annular patch designs is investigated and compared with a high end choke ring antenna. Aspects considered are size, bandwidth, radiation patterns, axial ratio, multipath performance and phase center. Finally, size reduction of the shorted annular patch is discussed.status: publishe