Antenna selection for mission-critical mobility applications is a complex and challenging task. While often an afterthought, the antenna is a fundamental component that dictates an entire system’s performance and resilience. RFI, with over 45 years of experience in critical communications, has designed and manufactured antennas to meet these challenges.
The challenge of modern mobility applications
In modern critical communications, a single vehicle can run multiple radios for different networks like LMR/PMR, cellular, GPS, and satellite. Accommodating all these antennas on one vehicle presents a significant challenge. Antenna design is constrained by physics, working against the limitations of space, vehicle height restrictions, and the demand for discrete designs.
Antennas for mobility applications are not one-size-fits-all. Each design involves a trade-off. RFI offers a broad range of antennas to meet various user needs, from low-profile and high-gain to on-glass and covert designs. The key is to prioritise which features are most important and where compromises can be made to ensure consistent and reliable performance. All RFI antennas are built with high-quality materials to withstand harsh environmental conditions.
Overcoming space and frequency limitations
The gold standard for vehicle antenna performance is a quarter-wave whip on a ground plane. However, this design has limitations, including a very narrow bandwidth and a potentially long whip at low frequencies. This can be problematic in modern installations where vehicles require multiple antennas.
The complexity of modern networks means that a single vehicle may need to support multiple technologies and frequencies. For example, cellular radios now need to cover 6-8 bands, compared to just one or two in the 1990s. Similarly, many police and fire agencies now use both VHF and UHF frequencies. This makes it impossible to use a separate narrowband antenna for every required frequency, making multiband or broadband antennas a necessary solution.
RFI has developed advanced engineering to create wide and multiband antennas that overcome typical design issues. RFI’s antennas, like the CD61 and CD30 series, provide exceptional performance that approaches that of single narrowband antennas. RFI has also developed ground-independent antennas, which allow for flexible mounting locations on light bars, bonnets, or gutters, freeing up the limited roof space. This is a critical innovation since there’s only one centre of the roof, and emergency vehicles have unique rooftop equipment challenges.
Specialised and covert solutions
In addition to performance, critical communications applications sometimes require discrete or covert antennas. RFI has designed antennas for these unique needs, including on-glass and other alternative mounting options. While these designs may have certain trade-offs in performance, such as restricted bandwidths and lower gain, they meet a very specific and critical requirement.
From the narrowband antennas of the past to today’s diverse and advanced range, RFI continues to innovate and adapt to the evolving needs of the critical communications market, providing reliable antennas for first responders in increasingly complex environments.
