Use rugged multiband antennas to solve the mobile connectivity challenge
(SNR) through the use of an active antenna with an integrated low- noise amplifier (LNA). As with all components, there are some top-tier parameters used to characterize nearly all antenna designs and installations, as well as others which may be more or less critical in a given situation. For antennas, radiation patterns and performance across the specified band are key considerations. Implementing antenna principles The orientation of antennas used for transportation and asset tracking is a challenge as it is
Along with smartphones and Internet of Things (IoT) devices, another major driver for mobile wireless connectivity is transportation applications, including railroads, trucks, and asset tracking.
These applications put a unique set of significant demands on the system antenna such as vibration, shock, temperature extremes, rain, humidity, and the need to operate across wide bandwidths and even multiple bands, all while providing consistent performance. While it is possible to design and build a suitable antenna, in nearly all challenging applications it makes the most sense to use a standard, properly designed, well-built, fully characterized, off- the-shelf unit. Doing so reduces cost and development time while increasing the level of confidence in the final design. This article examines the issues associated with transportation antenna design. It then introduces two multiband antennas from TE Connectivity designed to mount on the surface of an enclosure, including a basic ‘box’ and possibly an exposed moving vehicle.
free-space electromagnetic (EM) fields, and so is often the most exposed element of the design. Yet it must deliver the desired electrical and RF performance despite harsh ambient conditions, using a form factor compatible with the overall system design. For freight systems and especially high-speed passenger rail, it must also be easily integrated into an aerodynamic enclosure that both presents minimal wind resistance and can be protected from harsh environmental conditions (Figure 1). Similar constraints apply to asset tracking situations where the antenna must be exposed for receiving global navigation satellite system (GNSS) signals. The optimal antenna is a careful blend of application-specific characteristics, including desired radiation patterns, proper impedance match, low voltage standing wave ratio (VSWR), mechanical integrity, enclosure suitability, and ease of electrical connections. There is also the need in many cases to enhance the signal path and to maximize the front-end signal-to-noise ratio
Written by: Bill Schweber, Contributing Author at DigiKey
Figure 1: Mobile connectivity using various standards and bands is now an expectation on mobile, high-speed installations such as trains, incurring challenges due to wind resistance and environmental ruggedness. Image source: TE Connectivity
Applications drive implementation
The antenna is the vital transducer between an electronic circuit and
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