Title :
Comparative study of high performance GPS receiving antenna designs
Author :
Ortigosa, J.I. ; Padros, N. ; Iskander, Magdy F.
Author_Institution :
Utah Univ., Salt Lake City, UT, USA
Abstract :
A major factor in the performance of a differential Global Positioning System (DGPS) ground station is the performance of the antenna. The article analyzes and compares the performance of different GPS antenna designs. The specifications for the DGPS ground station antenna include hemispherical coverage and good multipath rejection. Good multipath rejection can be achieved by using an antenna that presents circular polarization and sharp drop-off at low elevation angles. In more detail, the specifications for the high precision GPS antenna include right hand circular polarization with a minimum of 15 dB of cross polarization rejection, hemispherical coverage presenting a variation of less than 3 dB over the main beam and a drop-off rate larger than 1 dB/deg for elevation angles from -5 to 5 deg. These specifications should be satisfied at the frequencies of 1.227 GHz and 1.575 GHz. The antenna designs examined in our study include patch antennas, helical antennas and conical spiral antennas. The numerical results from a successful conical spiral antenna design were verified experimentally.
Keywords :
Global Positioning System; conical antennas; electromagnetic wave polarisation; helical antennas; interference suppression; microstrip antennas; radiofrequency interference; receiving antennas; satellite antennas; spiral antennas; 1.227 GHz; 1.575 GHz; DGPS ground station; GPS receiving antenna; UHF; circular polarization; conical spiral antennas; cross polarization rejection; differential Global Positioning System; drop-off rate; elevation angles; helical antennas; hemispherical coverage; high performance antenna; low elevation angles; multipath rejection; patch antennas; right hand circular polarization; Cities and towns; Feeds; Frequency; Global Positioning System; Helical antennas; Patch antennas; Polarization; Receiving antennas; Satellite ground stations; Spirals;
Conference_Titel :
Antennas and Propagation Society International Symposium, 1996. AP-S. Digest
Conference_Location :
Baltimore, MD, USA
Print_ISBN :
0-7803-3216-4
DOI :
10.1109/APS.1996.549989