Abstract :
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 higher than those of regular dual-band cellular phone antennas. To satisfy all these requirements, a multiple-element antenna is designed, built, and measured.
Keywords :
Global Positioning System; active antennas; emergency services; low noise amplifiers; mobile antennas; preamplifiers; AMPS/PCS/GPS active antenna; GPS LNA; GPS low-noise amplifier; antenna-to-antenna isolation; cellular phone antenna; data exchange; dual-band cellular phone; emergency call systems; global positioning system antenna; multiple-element antenna; preamplifier filtering; vehicular emergency call applications; Antenna measurements; Cellular phones; Dual band; Filtering; Global Positioning System; Low-noise amplifiers; Noise figure; Passive filters; Personal communication networks; Preamplifiers; Amplifiers; antenna measurements; global positioning system; mobile antennas;
