Connect your external antenna with an LMR400 low loss cable that helps limit signal loss along the cable run. With N male at one end and SMA male at the other, it connects an antenna with an N female connector directly to compatible equipment with a standard SMA female port, such as a router, modem or mobile signal booster.
Choose 10, 20 or 30 metres to position the antenna separately from the equipment. This is useful when the antenna needs to be mounted higher up or on another part of the building to achieve better reception conditions.
LMR400 Ultra Low Loss is a practical choice when cable attenuation matters, particularly over longer runs. Losses vary with frequency and cable length. The attenuation table below provides values per metre alongside calculated losses for each available length.
The N male to SMA male configuration also simplifies wall routing. The smaller SMA connector can pass through a smaller opening than the N connector requires. You can keep the pre-fitted connectors in place without crimping the cable yourself.
With an outer diameter of 10.3 mm, the cable is thicker than slim antenna cables while remaining relatively bendable for planned routing. It features 50 Ω impedance and a stated temperature range of −40 to +85 °C for installation and operation.
A practical solution for a carefully planned antenna installation with pre-fitted connections and low cable attenuation. Choose the shortest length that reaches the intended antenna position to keep total signal loss down.
✅ Benefits
- LMR400 Ultra Low Loss – helps limit cable attenuation.
- Three length options – choose 10, 20 or 30 metres.
- N male to SMA male – connects directly to matching N female and SMA female ports.
- Easier wall routing – the smaller SMA connector requires a smaller opening than the N connector.
- Pre-fitted connectors – no crimping or connector assembly required.
- 50 Ω impedance – for compatible antenna and RF systems.
- Detailed attenuation values – help you select a suitable cable length.
- Wide temperature range – specified for installation and operation from −40 to +85 °C.
🎯 Ideal for
- External antennas with N female connectors connecting to equipment with SMA female ports.
- Compatible routers, modems and mobile signal boosters.
- Installations with an antenna mounted on a wall or mast, separately from the equipment.
- Wall routing where the smaller SMA end simplifies cable entry.
- Antenna installations requiring 10–30 metres of cable with low attenuation.
🔧 Connection and use
Measure the complete cable route and choose 10, 20 or 30 metres. Include corners, wall entries and the distance to the connection points.
Pass the SMA end through the wall before connecting the cable. Size the opening for the connector’s largest external dimension and any protective sleeve or gland. The 10.3 mm cable diameter is not the connector diameter.
Connect the N male connector to the antenna’s N female connector and the SMA male connector to the equipment’s standard SMA female port. Support the cable so its weight does not pull on the connectors, and use gentle bends.
Protect exposed connections and cable entries against moisture. Installations with multiple antenna feeds, such as MIMO, require one separate cable per antenna feed.
Longer cables introduce greater attenuation. Balance antenna positioning against cable length and avoid unnecessary extensions and adapter joints.
📡 Capacity and connections
| Feature | Details |
|---|
| Function | RF connection between antenna and equipment |
| Connector 1 | N male |
| Connector 2 | SMA male |
| Matching connections | N female and SMA female |
| SMA variant | Standard SMA |
| Connector locking | Threaded |
| Cable type | LMR400 |
| Impedance | 50 Ω |
| Available lengths | 10, 20 and 30 m |
| Signal paths | One coaxial signal path per cable |
📉 Cable attenuation at different frequencies
| Frequency | Attenuation per metre | 10 m | 20 m | 30 m |
|---|
| 30 MHz | 0.024 dB/m | 0.24 dB | 0.48 dB | 0.72 dB |
| 50 MHz | 0.030 dB/m | 0.30 dB | 0.60 dB | 0.90 dB |
| 150 MHz | 0.050 dB/m | 0.50 dB | 1.00 dB | 1.50 dB |
| 220 MHz | 0.061 dB/m | 0.61 dB | 1.22 dB | 1.83 dB |
| 450 MHz | 0.089 dB/m | 0.89 dB | 1.78 dB | 2.67 dB |
| 900 MHz | 0.128 dB/m | 1.28 dB | 2.56 dB | 3.84 dB |
| 1500 MHz | 0.168 dB/m | 1.68 dB | 3.36 dB | 5.04 dB |
| 2000 MHz | 0.196 dB/m | 1.96 dB | 3.92 dB | 5.88 dB |
| 2500 MHz | 0.222 dB/m | 2.22 dB | 4.44 dB | 6.66 dB |
| 5800 MHz | 0.355 dB/m | 3.55 dB | 7.10 dB | 10.65 dB |
Values for each cable length are calculated from the stated attenuation per metre. Connector and adapter losses are additional.
⚙️ Technical specifications
| Feature | Specification |
|---|
| Product type | Coaxial antenna cable |
| Cable designation | LMR400 |
| Cable construction | Ultra Low Loss |
| Connector combination | N male to SMA male |
| Connector assembly | Pre-fitted |
| Outer diameter | 10.3 mm |
| Impedance | 50 Ω, stated at 200 MHz |
| Installation and operating temperature | −40 to +85 °C |
| Colour | Black |
| Length options | 10 / 20 / 30 m |
| Quantity | 1 cable in the selected length |
📦 Package contents
- 1 × LMR400 low loss antenna cable with N male and SMA male connectors, in the selected length: 10, 20 or 30 metres.
