Difference between antennas lengths?

[pablo101]

This has got me a little confused. What is the difference between a 15dBi omni directional antenna which is 37cm in length, compared to one which is 130cm in length. I mean they're both the same power, both omni directional, will the longer one be better??

See the 2 links here to understand what i mean

HXXP://cgi.ebay.co.uk/2-4GHz-15dBi-Wireless-WIFI-Network-WLAN-Aerial-Antenna_W0QQitemZ390114351347QQcmdZViewItemQQptZUK _Computing_Networking_SM?hash=item5ad4a098f3#ht_26 17wt_878

HXXP://cgi.ebay.co.uk/15dBi-Long-Range-Extender-WiFi-Omni-Antenna-external-15_W0QQitemZ350315476805QQcmdZViewItemQQptZUK_Comp uting_Networking_SM?hash=item51906df745#ht_1635wt_ 878

[Thorn]

They are two different designs for two different applications

Define what you mean by "better". Better yet, describe what you want to do with an antenna. Antennas need to fit the function.

[chris_heyward]

The long range one you're looking at would be better. The reason being, you can create a wide area network(so no need for multiple antenna's) its weather proof so you can stick it on your roof and pick up your Wi-Fi signal from about half a mile away(if you fancy going for a walk with your laptop). My old workplace had one and I could pick my PC up so i was streaming my music. I was astonished by the signal. I was thinking about getting one. but as my AP is only on the other side of the wall, I have no need.