Published on 10/13/2026
A LoRaWAN gateway is indoors while the antenna is mounted above the roof line. Moving the antenna improves visibility, but a long thin feeder can consume much of that benefit. The right cable is the one that preserves useful margin without creating an unsafe or noncompliant installation.
Use 50 ohm coax with the correct regional band, connector interfaces and measured feeder-loss budget for a LoRa or LoRaWAN gateway. 868 MHz and 915 MHz are common shorthand, not globally interchangeable operating plans. Check the gateway, antenna, regional configuration and local rules together.
This guide focuses on the gateway-to-antenna path. It does not promise a fixed range from cable type or give one universal legal transmit-power limit.
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EU868 and US915 refer to different regional channel plans. A cable can often cover both electrically, but the gateway filters, radio configuration and antenna must match the actual plan. A gateway labelled 915 MHz is not automatically suitable for another region.
For an India deployment, check the applicable regional plan and current local authorization rather than copying an 868/915 MHz label. LoRaWAN regional parameters include IN865; the deployment's legal conditions must be confirmed with the responsible operator.
| Ordering item | What to specify |
|---|---|
| Frequency | Complete required uplink and downlink bands |
| System impedance | 50 ohm antenna path |
| Gateway port | Connector family, gender and standard/reverse polarity |
| Antenna port | Independent mating-face description |
| Feeder | Exact cable construction, length and loss limit |
| Region | Gateway channel plan and verified local operation requirements |
Cable loss reduces transmitted power at the antenna and weakens received signals reaching the gateway. It is not a transmit-only concern. A gateway can receive weak uplinks while also transmitting downlinks; the feeder matters in both directions.
Calculate cable loss from attenuation at the actual band multiplied by length, then add connectors, adapters and protectors. Use measured complete-assembly loss when available. A short internal pigtail can use thin coax; a long outdoor route may need a larger low-loss feeder.
Do not add a high-gain antenna without checking effective radiated power and coverage pattern. A narrower vertical pattern can help some links and hurt others. Lower-loss cable also raises delivered antenna power for the same transmitter setting, so verify the resulting system configuration.
Key idea: The best antenna location can still be worthwhile after feeder loss, but measure the trade-off rather than assuming every higher mounting point wins.
Get the interface right before ordering
Send the equipment-port details, cable length and operating band to SigmaRF.
Specify a Custom AssemblyGateways and antennas can use SMA, RP-SMA or N-Type interfaces. Confirm each mating face; Wi-Fi-style appearance does not establish polarity. The SigmaRF SMA vs RP-SMA identification guide provides the pin/socket and thread table.
Use a suitable outdoor jacket, seals and strain relief. Weatherproofing must protect the complete mated connection and cable entry, not only a connector advertised as sealed. Keep water from tracking down the cable into the enclosure.
A roof installation may need grounding, bonding and a suitable surge-protection design. Do not treat a surge protector as guaranteed protection from every lightning event. Check its insertion loss, frequency band and power rating, and have the installation follow applicable electrical and site requirements.
If practical, move the gateway closer to the antenna and carry data or power over a suitable non-RF route. This can reduce coax loss, but introduces weather, power, maintenance and network requirements. Evaluate the whole installation rather than moving equipment into an unqualified outdoor box.
When coax is unavoidable, route it without tight kinks, crushing or unsupported weight on equipment ports. A larger feeder can require a short flexible transition near the gateway. Include that transition's loss and mechanical support in the design.
Read SigmaRF's RG58 vs LMR-240 comparison for compact feeder data and its RF Link Budget Basics guide for a full path calculation. This article keeps the focus on sub-GHz gateway installation decisions.
For a hypothetical transmitter setting of 14 dBm, antenna gain of 5 dBi and complete feeder loss of 2 dB, calculate EIRP. This is arithmetic only, not a statement that the resulting setting is legal in any region.
Use antenna gain in dBi for EIRP. ERP uses a different antenna reference. Account for tolerances and the actual operating channel. A loss calculation does not replace local compliance review.
What cable should I use for a LoRa gateway antenna?
Use a 50 ohm assembly that meets the actual regional band, feeder-loss limit and installation conditions. Short pigtails and long outdoor runs often need different cable constructions.
How long can an 868 MHz or 915 MHz antenna cable be?
There is no universal limit. Set an allowable loss budget, include accessories and choose cable attenuation at the actual band. Antenna placement and gateway sensitivity determine the useful trade-off.
Can one cable work for EU868 and US915?
A suitably rated coax assembly can cover both bands, but gateway configuration, antenna and local operating rules are separate. Electrical cable bandwidth does not establish regional compliance.
Does lower-loss cable improve LoRa reception?
It reduces attenuation between antenna and gateway, which can preserve received signal margin. It does not remove interference, fix a poor antenna pattern or guarantee a specific range.
Do LoRa gateways use SMA or RP-SMA?
Either can appear, and N-Type is also used. Inspect the actual port and specify threads and center contact. Do not order from the application name alone.
Do outdoor LoRa antennas need surge protection?
Evaluate grounding and surge protection for the site and applicable requirements. Verify accessory band and loss. No small protector guarantees survival of every lightning event.
Choose the feeder from the installation budget, not a generic cable-length limit. Confirm region, interfaces and loss before buying, then support and protect the outdoor path.
A quote should include the actual band, both connector details, length reference planes, allowable loss and outdoor requirements. Review the complete system after changing the antenna or feeder.
SigmaRF VNA-sweeps every assembly for VSWR and insertion loss before shipment. Its testing capability spans 100 MHz to 40 GHz; each assembly is specified for its own operating band. Builds are supported by the Vadodara volume facility and Cleveland-area precision facility. Lead times can be as short as 2 days, depending on the build and component availability.
Get the interface right before ordering
Send the equipment-port details, cable length and operating band to SigmaRF.
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