the challenge.
Field observations showed a clear pattern: communication performance deteriorated shortly before kick-off. At that moment, the RF environment becomes increasingly congested due to broadcasting equipment, WiFi infrastructure and spectator devices operating in the 2.4 GHz band, pushing the C/N ratio of the BLE link too low for reliable data collection. The challenge was not only to understand the source of the interference but also to determine which hardware parameters offered the greatest opportunity for improvement.
We worked on this project together with Demcon multiphysics, experts in simulations.
electromagnetic simulations first
Demcon multiphysics first dived into the problem through an exploratory simulation campaign. Initial electromagnetic simulations were used to identify the most influential design parameters. The analysis showed that antenna positioning relative to the PCB strongly affects both resonance behavior and radiation performance. These insights provided the basis for further experimental validation.
measuring antenna performance under realistic conditions.
To validate antenna behaviour in practice, Demcon electronics performed a series of RF measurements in its anechoic chamber. These measurements focused on both the athlete-worn tracker and the Smarthub receiver, enabling the team to quantify the impact of antenna positioning, body absorption and polarisation effects.
Our anechoic chamber in Deventer (7.5 x 4 x 4m) provided a reflection-free environment essential for accurate antenna and radiation pattern measurements. The measurement setup consisted of a Vector Network Analyzer (Copper Mountain PLANAR R54), a spectrum analyser (Rigol DSA875TG), an ASTRO 18S horn antenna and a motorised rotating turntable.
A critical product requirement is the effect of the human body on the BLE signal from the tracker. The tracker is worn in a pouch on the player's back, and the body both absorbs and reflects electromagnetic radiation. To measure this, a colleague wore the sports vest with the tracker while the turntable completed a full 360° rotation over 60 seconds.
The measurement clearly shows that the human body attenuates the signal by approximately 4 dB, equivalent to a factor 1.6 reduction in effective range. Furthermore, the horizontal polarisation is dominant: it carries 6.67 dB (4.7×) more radiated power than the vertical polarisation. The recommendation was therefore clear: the Smarthub must prioritise reception of the horizontal
measurement results.
Measurements showed that the existing tracker antenna already performs close to the practical limits imposed by the compact enclosure and the human body. As a result, the highest improvement potential was found on the receiver side of the system, leading the project team to focus on the Smarthub architecture.
optimising the receiving antenna.
The largest gains were achieved by redesigning the receiving side of the communication link. Through a structured measurement campaign, multiple antenna and reflector configurations were evaluated to determine the relationship between antenna placement, radiation pattern and received signal strength.
Using the anechoic chamber, engineers evaluated how antenna position, orientation and surrounding structures influence radiation characteristics and receiver sensitivity. Multiple configurations were tested to determine which setup would provide the most robust communication under stadium operating conditions.
To better understand the interaction between the antenna and nearby conductive surfaces, a dipole antenna was positioned at different distances (20 to 60 mm) from a metal reflector representing the electronics assembly behind the antenna. Radiation patterns and gain were measured for each configuration and compared with a free-space reference measurement.
The results revealed a clear optimum. Positioning the antenna approximately 30 to 40 mm from the reflector produced a significant increase in antenna gain. At the optimal distance, the measured gain improvement reached 9.8 dB compared to the baseline configuration. This translates to a substantially larger link margin, enabling the receiver to maintain reliable communication even in RF-challenging environments where interference levels are high.
Further measurements revealed opportunities to improve antenna orientation within the Smarthub design. The team observed that the measured beam shaping differed from initial expectations, prompting additional investigations into alternative antenna arrangements. One of the concepts under evaluation is the use of alternating ±45° antenna orientations to reduce coupling effects while maintaining reliable reception regardless of player orientation on the field.
the impact.
The insights gained from the RF measurements were translated into an updated antenna design for the Smarthub. Several units were equipped with the optimised antenna configuration and deployed under real operating conditions.
Field results confirmed the laboratory findings. Users reported noticeably improved connection stability during training sessions and matches, particularly in environments with high levels of wireless activity. Comparative measurements also demonstrated a reduction in communication dropouts compared with the previous antenna implementation.
By combining simulation-driven insight with targeted RF characterisation and antenna validation, the project delivered a practical improvement with immediate value for end users. Rather than redesigning the complete system, the optimisation focused on the components with the greatest performance impact, resulting in a faster and more cost-effective route to enhanced wireless reliability.
| Phase | Goal | Approach | Outcome |
|---|---|---|---|
| Simulation ā Demcon multiphysics | Quick iteration and root cause analysis | COMSOL EM simulation | Ground plane significantly affects S11 and radiation patternm |
| Tracker measurement ā Demcon electronics | Realistic performance validation (incl. body) | Anechoic chamber measurements with body model | Body attenuates ~4 dB; horizontal polarization dominant (+6.67 dB) |
| Smarthub optimalisation | Identify high-impact design parameters | Dipole + flat reflector at 30ā40 mm | +9.8 dB gain vs. free space |
| Antenna validation | Verify performance under realistic operating conditions | Simulation and anechoic chamber measurements | Optimized patch antenna configuration selected for deployment in the field |
measure. understand. improve.
"Every wireless system faces interference. The difference lies in knowing how to measure it, understand it and overcome it."