External antennas connect to wireless devices via a cable. Unless you are very short, it is normal that the cable between the wireless device with the antenna coaxial cable, similar to the TV antenna but with a different impedance. We talked about 50 ohms compared to 75 ohms are usually the typical television. So not worth the standard cables used in equipment for reception of digital terrestrial or analog TV. Coaxial cables are characterized because they have a hub (usually called active) surrounded by a concentric metal mesh that protects it from interference that many in the field that usually operate radio cards and access point, cable TV is a good example of coaxial cable but as we said is not true for wireless networks.
To connect the cable to the antenna and wireless devices, connectors are used. Both the antenna and some teams where wirelessdisponen a connector must be plugged their corresponding connectors on the cable ends. To carry out this operation, there are some known connectors such as male and others as female type. It is obvious that only opposite-sex connectors can connect with each other. For example, the antenna tends to have as we said earlier a female type connector and the possible, a male type. This cable connects the antenna.
Both the cable and each connector, add losses to wireless radio signals. To avoid these losses, apart from using quality cables and connectors. must be taken to use a cable as short as possible and the number of connectors necessary. The number of connectors depends on the cards and antennas that we have, the quality will depend on our pocket and the length is determined by the type of cable you want to use, how expensive it is worth, by the distance to the antenna, in short by their loss, let's say we have a good antenna but for being too far to the wifi card and since our budget is limited the type of cable is the most evil, they are likely to lose the gain on the antenna. So appreciate all these aspects. Also try to avoid as much as possible to use connectors to extend the length of wired to accommodate different types of cables or connectors. Always reduce the maximum expression and joints between cables you ever do, if we need a longer, it is always best to adapt the system with a new cable but is less loss and therefore higher quality but more expensive in contrast.
Types of connectors.
The use of the connectors seem very simple, but everything is complicated by the fact that there is no regulation that specifies how they should be connectors. This entails that there are many different models of connectors. Some very widespread as the RP-SMA and other manufacturer-specific, so-called proprietary connector. For example, some used TNC connectors, other BNC, SMA others and / or RP-SMA (Reverse SMA) and some self-designed connectors. The fact is further complicated if we consider that the type of antenna connector of the connector is often different from the wireless cards. After a certain power of the type usually N-Female.
Most wireless devices (wireless adapters and access points and wireless routers, but remember that a wireless router is nothing more than a normal router which is incorporated an internal wireless access point) have a connector connect an external antenna. Access points and mostly comes with its own antenna. And as for the cards, the most common with this type of connector is being assembled on a desktop PC or PCI interface. Typically, all teams would be marketed with a connector to connect an external antenna, but as you know most of the USB interface cards and PCMCIA do not meet this requirement, and less Mini-PCI cards that are incorporated in laptops. And therefore we always try to handle this type of equipment with the risk that entails.
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