topic Re: Antenna Diversity Question in Wireless

Antenna Diversity Question

jclay — Mon, 05 Jul 2021 05:52:01 GMT

Are there specific distances that antennas should be placed to maximize the benefit of antenna diversity in an 802.11b compliant WLAN?

Re: Antenna Diversity Question

jaunger — Fri, 09 Nov 2001 22:50:12 GMT

Are you refering to antennas on an indoor access point or to antennas that are outside, say

on a roof?

Re: Antenna Diversity Question

ED CARMODY — Tue, 13 Nov 2001 02:07:32 GMT

Usually recommended is 10-20 wavelengths. A wavelength is a couple of inches at 2.4GHZ.

Re: Antenna Diversity Question

csthomas — Wed, 14 Nov 2001 22:54:12 GMT

For the type of fading that 802.11b is trying to combat, the signals from two antennas separated by even a wavelength are largely uncorrelated. Hence, even very small separations work.

The spacing is non-critical. Since the receiver is only using one antenna at a given time, you don't have to worry about the phase relationship between the two antennas. If you were using two antennas at once (typical in two-way radio and broadcast TV/FM, etc.), the spacing and length of feedlines is critical because there the phase matters.