antenna-theory.com

[ball]

Hi. I'm adding external antennas to a netgear router (the internal pc-board based antennas suck).

The router has three internal ports, but I'll only be using two of them for a couple long omnidirectional antennas.

What is the ideal distance for drilling the holes? I'm considering one wavelength or 1.5 wavelengths (a wavelength being 123mm for channel 6).

I measured a bricked linksys router which had the antennas 146mm apart for whatever reason.

Thanks.

[hagster]

The antennas in these Wi-Fi routers are designed for MIMO data transmission rather than as a conventional beam forming phased array. The idea is that each antenna has a distinct radio path to the device and can therefore (to some extent) transmit different data through each path to increase throughput. So ideally you should be aiming to maintain as much difference between the the antenna paths as possible. One method of doing this is to have different polorisation, hence you will see routers with 3 antennas at different slants. For directional antennas it's common to see patch antennas with horizontal and vertical feeds.

As to the best seperation my guess would be something like a 1/4 lamda or multiple thereof might make sense.

[ball]

Cool, so what orientation should I have the antennae?

3/4 λ would be about 92mm for channel 6.