Article | 2007 | IEEE Antennas and Wireless Propagation Letters6 , pp.488 - 491
Although GPS antennas are commonly used for vehicle applications, their on-vehicle gain patterns are not known well. Especially, when the antenna is mounted at locations other than the roof center, the antenna gain becomes directional at mid-to-low elevation angles. The goal of this letter is to investigate the GPS passive antenna performance at its actual, on-vehicle mounting locations. For four different antenna locations on a sedan vehicle with sunroof, the antenna gain is measured in a quasi-far-field antenna range. The results are also compared to those of finite ground plane, anechoic chamber measurements. © 2007 IEEE.
Article | 2007 | IEEE Antennas and Wireless Propagation Letters6 , pp.255 - 258
Many vehicular emergency call applications utilize a dual-band cellular phone for data exchange and Global Positioning System (GPS) antenna for localization. When the cellular phone antenna is transmitting in close proximity to the GPS antenna, the GPS low-noise amplifier (LNA) is expected to be not affected, i.e., remain linear during the operation. Most commercial GPS LNAs hardly meet this requirement, hence passive antenna-to-antenna isolation and preamplifier filtering without affecting the noise figure of the system becomes crucial. In addition, passive antenna gain requirements for emergency call applications are generally hig . . .her than those of regular dual-band cellular phone antennas. To satisfy all these requirements, a multiple-element antenna is designed, built, and measured. © 2007 IEEE