I Connected My Router To An External Antenna, Now My Performance Is Worse

Question: Why is my router performance worse AFTER I connected an external antenna?

Written by Stephen Froneman of Poynting

Here are some of the reasons you might be experiencing a worse performance after connecting an external antenna:

Internal / External Antenna Selection: Some routers have an option to select between an ‘Internal’ and the ‘External’ antenna. When connecting an external antenna, it is important to check this option is set correctly in the GUI settings. If this option is selected incorrectly, then the router will not gain any benefit from the external antenna. Not all routers have this option, so please check the router manual.

Damaged coax cables: Coaxial cables have different bend radius specifications which need to be observed and used during implementation. When a coax cable is bent or compressed, the inner materials may become damaged and will affect the performance of the wireless system. Damaged coax cannot always be seen from the exterior and needs to be tested to confirm its performance.


Incorrect impedance coax cable: When the incorrect impedance specification is used, this will cause a mismatch between the antenna and the radio of the router, which in turn may negatively affect the wireless system performance. It is important to ensure that the same impedance is used for the whole system e.g. using a 50 Ohm antenna with a 50 Ohm coaxial cable, with the 50 Ohm router or radio is necessary.

Water proofing connectors: Please also check that the connectors are protected from water ingress. Connectors that are exposed to water, even moisture, are known to suck water into the coax cable as the temperature fluctuations cause the cable to expand and contract through the day. The connectors therefore need to be sealed properly (or installed in a waterproof area).

Antenna alignment: When using a uni-directional antenna (aka directional antenna), then the alignment to the best base station is of utmost importance. Please see the FAQ titled: “How To Orientate A Directional LTE Antenna During Installation?” for more information.

Installation obstructions: Installing an antenna with obstructions (trees, buildings, etc.) very near to the antenna may cause the antenna signal to be obstructed. Although Line-of-Sight (LOS) is not always needed between the base station and the customer antenna, it is best to install the antenna such that it benefits from the least obstructions possible. For more information, see our webinar titled Factors affecting your #RF experience on this topic.

RPSMA connectors: An RPSMA connector is often mistaken for an SMA connector, and visa versa. (RPSMA connectors are normally reserved for Wi-Fi applications). We occasionally find customers connecting an RPSMA to an SMA connector; these connectors are partially compatible from a mechanical perspective, but they are not compatible electrically. Please ensure that the connectors are checked for this easy mistake.

Article originally posted on Poynting Website