Common two types of wireless antennas

The hardware devices of the wireless local area network are mainly composed of a wireless network card and a wireless AP, and the user can easily form a wireless network. In addition, if the transmission distance is long, the wireless gain antenna can also be used to extend the transmission distance.

(1) Wireless network card


The wireless network card functions like a network card in Ethernet, and acts as an interface of the wireless network to implement connection with the wireless network. If there are two computers, you can purchase two 802.11b wireless network cards directly connected to each other, with encryption function to prevent others from stealing wireless networks, which is much more convenient than wired networks. If there are three or more computers, you can use a wireless AP to form a wireless LAN. Wireless network cards are mainly classified into three types according to different interface types, namely, PCMCIA wireless network card, PCI wireless network card, and USB wireless network card. Common specifications for wireless network cards can be divided into 3M, 5M and 11M.

The PCMCIA wireless network card is only suitable for laptops and supports hot plugging, making it easy to implement mobile wireless access. PCI interface wireless network card is suitable for ordinary desktop computers. In fact, the wireless network card of the PCI interface only inserts a PC card supporting the wireless function on the PCI adapter card. USB interface wireless network card is suitable for laptops and desktops, and supports hot swap. If the wireless card is external to the network card, the USB interface will be a very good choice.

(2) Wireless AP

A wireless AP (Access Point) is also called a wireless bridge, a wireless gateway, or a wireless access point, and functions like a hub in an Ethernet. When a wireless AP is added to the network, the network coverage diameter can be expanded exponentially. In addition, it can also accommodate more network devices in the network. Under normal circumstances, an AP can support up to 80 computers, of course, the recommended number is 30.

Each wireless AP basically has an Ethernet interface for wireless and wired connections. In addition, many wireless APs also have extended functions, such as Ethernet switch port, routing, NAT, DHCP, print server and other functions, with the aid of ADSL or Cable Modem connection, Internet access sharing; printers can also be shared.

(3) Wireless gain antenna

When the computer is far away from the wireless AP or other computer, as the signal is weakened, or the transmission rate is significantly reduced, or communication with the AP or other computer is not possible at all, then the wireless antenna must be used. The received or transmitted signal is gained. There are many types of outdoor antennas, one is a pot-shaped directional antenna, and the other is a rod-shaped omnidirectional antenna. Generally, a small wireless LAN may not use a wireless antenna.