Lower or Higher dBi?

[FrodoRox]

for a PCIe wireless network adaptor, is a lower or higher dBi antenna better? and what are the pros and cons of higher or lower dBi antennas? also, what is an R SMA antenna? thanks in advance

 

[leeb2013]

higher has more gain, but less of a broad field pattern, meaning it'll go further but cover less area. Good if your far away and don't move stuff around, so you can position the antenna for best reception and leave it.

lower gain, covers a more broad area, but shorter distance. Good if you move stuff around.

 

[Someone Somewhere]

Higher dBi is more directional. More power, but in a narrower direction.

 

[STACKS ON DECK]

higher dBi means higher gain and antenna's range is now more then on lower dBi

 

[FrodoRox]

so how good would a 5dBi antenna be, and do walls or objects that are between the antenna and the router affect the connection strength in any way?

 

[STACKS ON DECK]

walls obstacles do weakens the signal . refraction of signals or fading or path loss can occur

 

[bill001g]

The antenna on the card is only a tiny part of the question. You would have to try to find the specs on the cards and determine which radio chipsets they are using and try to determine at what levels the radios transmit. These also are rated in Db but they are also rated in milliwatts.

So the actual transmit power is a function of the radio and the antenna. Most times these numbers are closely matched. Certain radios work better transmitting more power and using smaller antenna and some like to transmit less power but use larger antenna. This is why putting bigger antenna on a card does not always increase usability of the signal. It may increase the total signal strength but it also increases the noise in the signal.

There are people who make their whole career design of antenna systems because it is such a complex subject.

In general you will not see huge difference between nic cards, almost all transmit at the legal maximum power. Things like the walls in your house have a much large impact that tiny difference between cards. When you use a internal card one of the biggest signal blockers is the metal case of the machine. Be sure you the antenna facing toward your router if at all possible. Stuffed under a desk against the wall tends to be the worst place for wireless cards but that is where people tend to put desktops.