Connector Guide

Antenna Connector Types — SMA N-Type TNC FME IPEX

Which connector is on your router, which is on your antenna, and how to seal every outdoor joint correctly.

SMA

50 ohm, most IoT routers

N-Type

Weatherproof, preferred outdoor

TNC

SMA with weather thread

U.FL/IPEX

Micro, embedded PCB use

Connector Type Reference

Connector	Impedance	Frequency Max	Typical Use	Weather Seal
SMA	50 Ω	~26 GHz	IoT routers, test equipment	Needs tape
RP-SMA	50 Ω	~26 GHz	WiFi consumer APs	Needs tape
N-Type	50 Ω	~11 GHz	Outdoor antennas, base stations	Better inherently
TNC	50 Ω	~11 GHz	Industrial, GNSS equipment	Threaded, good
FME	50 Ω	~1 GHz	Vehicle antennas, thin cable	Needs tape
U.FL / IPEX	50 Ω	~6 GHz	PCB-level, embedded modules	Indoor only
SMA (female bulkhead)	50 Ω	~26 GHz	Panel feedthrough	With gasket

Identifying Your Router Connectors

All Teltonika cellular routers (RUT241, RUT360, RUTX11, RUTX50, RUT956) use SMA female jacks. Connect SMA male plugs from your antenna cable. Most Peplink routers use SMA female jacks. Sierra Wireless routers vary — check the datasheet. Robustel routers typically use SMA female. Cradlepoint uses SMA female on most models.

For WiFi access points used in IoT gateways: check carefully. Ubiquiti devices typically use N-type female. Consumer-grade Netgear, TP-Link use RP-SMA female. Professional IoT-grade APs vary.

Outdoor Connector Weatherproofing

Every outdoor SMA or N-type connection will eventually fail without proper weatherproofing. Water ingress into a coaxial connector causes corrosion at the centre pin, dramatically increasing insertion loss and VSWR. On LMR-240 with good connectors, the measured loss might be 0.13 dB/m. With corroded connectors, the additional loss can be 2-3 dB at a single joint — equivalent to 15+ metres of good cable.

Weatherproofing method: clean and dry the connector, apply one wrap of 19mm PTFE tape, then two overlapping wraps of self-amalgamating tape from 25mm below to 25mm above the connector. For mast-top or exposed roof installations, apply a further wrap of UV-stable PVC tape over the self-amalgamating tape.

Frequently Asked Questions

What is the difference between SMA and RP-SMA?

SMA (SubMiniature version A) has a male centre pin. RP-SMA (Reverse Polarity SMA) reverses the centre conductor — the male RP-SMA plug has a socket (female centre pin). They look nearly identical and the threads are compatible. Do not connect them — if an RP-SMA plug fits an SMA jack it will mate but make no electrical connection. Industrial IoT routers (Teltonika, Peplink, Sierra) use SMA. Consumer WiFi routers and access points typically use RP-SMA.

Should I use SMA or N-type connectors for outdoor installations?

N-type for any permanent outdoor installation if your router supports it. N-type has a larger contact area, better mechanical strength, and a weather-resistant bayonet locking ring. SMA is fine for most outdoor applications but the small size makes it more vulnerable to damage and connector creep over years of thermal cycling. Where you have a choice, use N-type outdoor with an SMA adapter at the router, rather than SMA throughout.

What self-amalgamating tape should I use on outdoor connectors?

Use proper coaxial connector weatherproofing tape, not standard insulating tape. Self-amalgamating tape (also called self-fusing or rubber splicing tape) bonds to itself without adhesive and creates a watertight seal. 3M 23 tape is the industry standard. Wrap from 25mm below the connector, over the connector body, and 25mm up the cable. Two layers minimum. The tape should stretch by 30-50% as you apply it for proper bonding.

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