The growing demand for data driven analysis for shipping and logistics is driving up the need for modern vehicle tracking, telematics, navigation systems, fleet management, and eventually, autonomous vehicles. All of these systems are intrinsically reliant on global positioning system (GPS) and other global navigation satellite system (GNSS) technologies. GNSS often includes support for satellite systems other than GPS, such as GALILEO, BeiDou, and GLONASS. For cars, trucks, fleet vehicles, off-road vehicles, and other automobiles, it is critical to have a GPS/GNSS antenna system that is able to deliver a reliable communication link even when exposed to the rugged conditions of the open road or off-road environment. This is where rugged Vehicle GPS/GNSS Antennas come into play.
These GPS systems differ from the GPS/GNSS antennas that are typically located in GPS/GNSS electronics, in that they are external antennas that are connected via coaxial connectors to a GPS/GNSS port on modern cellular modems, location tracking units, or fleet vehicle management units. These GPS/GNSS antennas are designed to be mounted on the outside of the vehicle for optimal signal strength compared to being located within a vehicle that may likely shield or otherwise attenuate GPS/GNSS signals. As these antennas are located on the outside of vehicles they need to be reliably performed in tough conditions. A key aspect of external vehicle operation for antennas is the ability to mount in a variety of ways, including being able to be screw mounted for permanent installations and strong magnetic mounting for temporary installations or when ease and speed of installation is top priority.
Other considerations for vehicle mounted GPS/GNSS antenna are to have SMA and FAKRA connector options. SMA is the most common coaxial connector type used commercially for GPS, but many military/defense, government, and industrial applications also may use FAKRA connectors. The polarization of GPS/GNSS antennas also matters. Right hand circularly polarized antennas can help by providing cross-polarization isolation (left hand circularly polarized signal rejection) and improved sensitivity (lock-time). Other critical features include a low-profile against the mounting surface to reduce drag and the chance of being struck by road debris or wind driven weather.
These antenna types often include integrated low-noise amplifiers (LNAs), as GPS/GNSS signals are extremely weak. Even the small loss along a coaxial cable from an external antenna to a GPS/GNSS receiver located within a vehicle would be significant for the sensitivity of the GPS/GNSS system. Hence, LNA noise figure (NF) is also a consideration for these antennas.