Ultra-Wideband Tracking Greater Precision in UWB Positioning Through Improved Antenna Design

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Precise UWB positioning in compact form factors is often hindered by physical obstacles such as tissue absorption and detuning. Tags placed directly on biological tissue or metal suffer from reduced signal quality. An improved antenna design solves these problems and improves the link budget.

The main problem with any radio transmission near the body is the near-field electromagnetic field. Due to its high water content, biological tissue acts as a strong absorber, which leads to a significant loss of radiation efficiency in conventional UWB antennas. Added to this is the problem of non-line-of-sight (NLoS) conditions: as soon as the object being tracked moves or is obscured by an obstacle, a standard system loses its stable connection. In practice, or when tracking mobile assets, this results either in data gaps or in a drastic increase in energy consumption, as the system attempts to compensate for the losses through more frequent transmission cycles.

Electromagnetic Waves Surround the Body

This is where the BodyWave technology developed by AntennaWare comes into play. The engineers have created an antenna design that is specifically optimized to shape the electromagnetic waves so that they, in a sense, flow around the barrier presented by the body or the mounting surface. In direct comparison to conventional chip antennas, the link budget improves by 6 to 12 dB. For system developers, this value is a critical factor: A gain of 6 dB physically corresponds to a doubling of the range in open space or, conversely, allows for a massive reduction in transmit power while maintaining the same range, which significantly extends the battery life of the end devices.

Icoteq’s TagRanger system demonstrates just how effective this approach is in real-world conditions. The system uses a hybrid wireless architecture that could serve as a model for many IoT scenarios. Long-range communication and the transmission of telemetry data are handled via the power-efficient LoRaWAN protocol, while the UWB unit is activated only at close range for high-precision localization. It was only through the integration of specialized UWB antennas that it became possible to ensure that positioning remains stable even when the tag is located under dense vegetation or in a position unfavorable for radio waves. In field tests, a lost tracker could thus be located with centimeter-level accuracy even in challenging environments.

Uniform Radiation Pattern

A key technical aspect highlighted by Icoteq CEO Craig Rackstraw is the uniformity of the radiation pattern. Many compact antennas exhibit pronounced nulls in the pattern, where almost no energy is radiated. BodyWave technology has made it possible to achieve a nearly ideal 360-degree pattern. Thanks to this uniformity, it is possible to reliably measure distances (ranging) and prevent jumps in position determination caused by changing tag orientations.

The application of this technology extends far beyond ecological research. What works for wild animals essentially paves the way for industrial applications. After all, it doesn’t matter whether we’re talking about humans or animals—the physical problem remains the same. Anyone who tries to simply overcome dead zones or signal loss with more transmit power will run into a problem with battery life. The better approach lies in RF design. If the antenna is designed to handle difficult surfaces and obstructions, the entire system becomes not only more precise but also significantly more durable. In the end, it’s not the size of the battery that determines the success of a tracking system, but the sophisticated antenna design. (heh)

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