Fleet and Telematics Antenna Solutions: Combined Cellular, GNSS and Wi-Fi
A telematics unit needs three radios in one small footprint on a vehicle roof: cellular for the backhaul, GNSS for position, and often Wi-Fi for depot offload. The roof is the only place with a clear view, and it is exactly where space, height and appearance are most constrained. RF element builds combined puck antennas, low-profile domes and router antennas for fleet and telematics installations.
What constrains a roof-mounted antenna
One footprint, three bands, mutual interference
Cellular, GNSS and Wi-Fi antennas placed too close together couple into each other, and the GNSS front end is the usual victim because its signal is weakest. Physical spacing, filtering and a defined ground plane matter more than adding gain to any single element.
The roof is a poor ground plane
A vehicle roof is curved, seamed and often partly plastic. A GNSS antenna needs a reasonably flat metal plane to hold its pattern and phase centre; mounting it on a plastic fairing or at the edge of the roof shifts the pattern and raises multipath.
Vibration, car washes and cable routing
A roof antenna passes under height restrictions, through brushes and along a cable path that is compressed by headlining. A sealed base, a low profile and a strain-relieved cable entry decide whether the unit survives the first year.
Antenna selection by deployment case
Selection is driven by the vehicle type and the services required. A van with a telematics box and a router needs different hardware from a bus with a passenger Wi-Fi system. The table maps the common cases to the antenna families we build.
| Antenna type | Frequency range | Gain | Typical use |
|---|---|---|---|
| GNSS + cellular puck | 700-3800 MHz + 1575.42 MHz | 3 dBi / 28 dB LNA | Tracking units and vehicle gateways |
| MIMO dome | 800-2600 MHz | 4-6 dBi | Low-profile roof mount, LTE MIMO |
| Router antenna | 2.4-2.5 / 5.15-5.85 GHz | 2-2.5 dBi | In-vehicle Wi-Fi routers |
| 5G router omni | 698-4200 MHz | 3-3.5 dBi | 5G vehicle routers and mobile hotspots |
Band, gain and polarization trade-offs
Roof space, not gain, is the binding constraint on a vehicle. A combined puck occupies roughly 80 mm of height; separate cellular and GNSS antennas need about three times the roof area and two cable runs, which is why the combined unit dominates telematics installations.
Cable loss dominates at cellular frequencies. Five metres of RG58 loses roughly 3 dB at 2.6 GHz, which is half the power; the same run in LMR-240 loses about half that, equivalent to doubling the antenna gain without changing the antenna.
Recommended antennas
Four models cover tracking, LTE routing, Wi-Fi and 5G. The puck combines cellular and GNSS in one housing; the others are single-service antennas for installations with more roof space.
5G IoT Antenna
4G LTE MIMO Omni Antenna
Dual Band WiFi Router Antenna
5G Router Antenna
Frequency, gain, beamwidth and connector values are taken from the linked product specification tables. Confirm the final configuration against the datasheet before ordering.
Installation and deployment notes
Roof installation is quick, and that is the problem: most failures are installation errors rather than antenna faults.
- Mount on a flat metal section of the roof, at least 100 mm from the edge, and avoid plastic fairings.
- Keep the GNSS element at least 150 mm from any cellular radiating element.
- Seal the cable entry with a proper gland and a drip loop; do not rely on silicone alone.
- Route the cable away from sharp edges and moving parts, and leave a service loop at the headlining.
- Check VSWR after installation and record it, so that a later fault can be told apart from a bad install.
Frequently asked questions
Can one antenna really cover cellular and GNSS?
Yes, and it is the standard solution for tracking units. The two elements share a housing but are separate radiators with their own feeds, and the GNSS path includes a low-noise amplifier. The key is the spacing and isolation between them, which is why the combined unit is preferable to two antennas crowded onto a small roof.
Do I need a ground plane?
For GNSS, yes: a metal plane under the antenna stabilises the pattern and reduces multipath. For cellular it improves the match and the radiation efficiency. If the roof is plastic, a metal plate under the antenna is the usual fix.
How much cable loss can I tolerate?
It depends on the band and the receiver. At 2.6 GHz, 5 m of thin coax can lose more than 3 dB, which is half the power. Use a low-loss cable for long runs, or move the radio closer to the antenna.
Are these antennas suitable for buses and trucks?
Yes, and the dome versions are the usual choice for buses because they are low-profile and resistant to brush washing. For trucks, check the height clearance before choosing a taller combined unit.
Related technical reading
Related industries
Vehicle-mounted antennas are constrained by the roof, the harness and the handover budget. The same constraints appear here.
What to send for an antenna shortlist
Send these five items and we can propose models with pattern data instead of a catalogue list.
- Vehicle type and roof material
- Services on board: cellular, GNSS, Wi-Fi
- Cable run length and connector type
- Height clearance restrictions
- Quantities and branding requirements
Send your layout, get an antenna shortlist
Tell us the vehicle type, the services on board and the roof material, and we will propose a combined or single-service antenna set with the cable plan.
Request a quotation