Router roof antenna - Page 1
Forum section: electronics / rf-microwave

author: antenna
author_rank: Frequent Contributor
timestamp: June 12, 2024, 01:47:25 am
content: I have a router that has three antennas (Netgear R7000P) and want to be able to use wifi on the small lake in front of the cabin. Can I put a directional antenna on just one of the antenna connectors and keep the other two little antennas doing the inside stuff, or do all three antennas need to be routed to the roof for the internet to work on the lake out front? I don't want to cover the whole lake and I don't intend to let many people use it, so speed is not that important. At most, streaming a radio station or checking the weather. I don't know how that MIMO stuff works or if extending just one of three will impact functionality.Thanks

author: Kim Christensen
author_rank: Super Contributor
timestamp: June 12, 2024, 02:53:00 am
content: I think those 3 antennas are supposed to work together like a phased array. This allows them to direct the majority of RF energy in the right direction. (Towards connected clients)Unless some of the antennas are fake. Either way, I doubt remoting a single antenna would work as expected. A better bet is to put a wired access point onto the roof. Or put a wifi router in bridge mode, or wifi extender, up there.

author: NiHaoMike
author_rank: Super Contributor
timestamp: June 12, 2024, 03:02:39 am
content: Get a second AP (a cheap one will do) and add a high gain antenna to it.

author: antenna
author_rank: Frequent Contributor
timestamp: June 12, 2024, 05:04:52 am
content: I was thinking about building a little box for it and installing the whole thing on the roof but our outdoor temps go from lows around-40°F in winter to highs of 105°F in the summer shade. Even with daytime variations I worry about solder joints cracking and caps leaking from the hot cold cycles.

author: antenna
author_rank: Frequent Contributor
timestamp: June 12, 2024, 05:21:08 am
content: Please explain the multi-antenna thing a bit more. A phased array/beamforming would have all the antennas carrying the same data, merely time shifted a little, and should have the requirement that the antennas be properly oriented (presumably parallel to one another).I've heard the router antennas should be oriented differently so it can switch antennas when the remote device antenna polarization changes, but that would interfere with the beam-forming theory.Two different theories that, IMO, can't coexist. Since they design the antennas to turn, I speculate that each antenna carries different data and beamforming is not the devices priority. But if the function is to communicate simultaneously on more than one channel with a single client, can it also identify, and work in, situations where that is not possible?I am wondering if I ran just one antenna to the roof, maybe a moxon aimed at the lake, if the router would detect communication only with that one antenna is possible and work to make the best of it. Would that one antenna be enough for limited connectivity, or would it simply not work without all three?

author: Bud
author_rank: Super Contributor
timestamp: June 12, 2024, 05:30:28 am
content: It cant be beam forming transmission, the antennas can be freely positioned by hand, and home routers do not have a logic for it. I'd think only one antenna transmitts, the other antennas are for Diversity reception, not transmission.

author: vk4ffab
author_rank: Frequent Contributor
timestamp: June 12, 2024, 06:54:22 am
content: Quote from: Bud on June 12, 2024, 05:30:28 amAll newer netgear routers do explicit beam forming and many of those also do implicit beam forming. Pretty sure at a minimum this requires 3 antenna, 1 antenna transmits and the other 2 are used to shape the radiation pattern of the transmitting antenna.

author: antenna
author_rank: Frequent Contributor
timestamp: June 12, 2024, 06:55:57 am
content: I just noticed beamforming is an enabled option in the router settings.If I uncheck that, and uncheck MIMO?

author: vk4ffab
author_rank: Frequent Contributor
timestamp: June 12, 2024, 06:56:17 am
content: Quote from: antenna on June 12, 2024, 01:47:25 amYou probably are better off buying a range extender that has a single antenna or dish and pointing that where you want it to go. Ubiquity comes to mind for all the usual high gain wifi solutions.

author: antenna
author_rank: Frequent Contributor
timestamp: June 12, 2024, 06:58:14 am
content: If it has beamforming, then I will just extend all three antennas to the roof and accept the coax loss.

author: vk4ffab
author_rank: Frequent Contributor
timestamp: June 12, 2024, 07:23:14 am
content: Quote from: antenna on June 12, 2024, 06:58:14 amU6 Mesh Pro from Ubiquity is only 200 yanky bucks. Covers 200sq m.

author: A.Z.
author_rank: Super Contributor
timestamp: June 12, 2024, 01:27:40 pm
content: Quote from: antenna on June 12, 2024, 01:47:25 amWilling to go for an OTS solution, you may consider this onehttps://www.tp-link.com/business-networking/outdoor-radio/cpe710/it's a WiFi "range extender" mounted straight on a parabolic reflector and powered using PoE, you pass a CAT-5 cable from your AP/switch up to the roof, use a PoE injector to power the unit and connect the cable to the antenna which you'll then aim as needed; if otherwise you prefer going for DIY, then you should buy a simple "extender", place it under the roof and connect it with a (as short as possible) run of coax to an antenna like the one described herehttp://www.trevor-marshall.com/biquad.htmfor further infos, also see herehttps://martybugs.net/wireless/biquad/HTHNotice that, at those frequencies, trees will represent an obstacle and will interfere with the "Fresnel zone"https://en.wikipedia.org/wiki/Fresnel_zone#/media/File:Fresnel_zone_disrupted.pngso consider that when installing the antennahttps://en.wikipedia.org/wiki/Fresnel_zone

author: Bud
author_rank: Super Contributor
timestamp: June 16, 2024, 06:30:25 pm
content: You cant have flimsy antennas flapping in the breeze that household routers have and have beamforming, this is bullshit. You'd need to have a rigid antenna structure, as one millimeter shift in relative positioning between multiple antennas will affect the beam.

author: antenna
author_rank: Frequent Contributor
timestamp: June 16, 2024, 08:29:11 pm
content: Quote from: Bud on June 16, 2024, 06:30:25 pmI planned on making a set of rigid antennas and mounting them facing the lake. I will have a second AP in the house if devices on the property can't work the back side of the antennas or the metal roof interferes. I am unsure what antennas to go with. Considering moxons and patch antennas but I am also tempted to try slot antennas. I like the idea of the moxons aimed at the lake because it's easy and I think everything else is close enough, but an array of slots to give me an omnidirectional pattern with a little down tilt would work good too since I am on a decent hill. The whole lake is only 90 acres, so I could probably cover the entire lake with wifi with an array. My experience has been limited to HF and VHF, no stripline/microwave stuff, so a slot array would be a new challenge.Another problem that I am unsure about is the wifi band. I am not going through the hassle of a dual band antenna. If I do, it would be the coupled radiator type. If I go with 5Gz only, I could probably find some soft copper tubing for use as waveguides instead of using coax, but 5GHz is blocked more by tree leaves and branches. With about 1.5m transmission line, thanks to this hill, I can get about 20m above the lake level, so maybe with some antenna gain and down tilt, that will make up for the coax loss. Considering TL losses, obstacles that block signals, being practical, I don't know whats best, 2.4GHz through coax, or copper tubing waveguide running 5GHz.

author: MartinL
author_rank: Regular Contributor
timestamp: June 20, 2024, 07:58:38 pm
content: The reason for multiple antennas on wifi routers is diversity. It gets you resilience against fading due to the client and router antennas being in orthogonal orientations, spots where multipath signals cancel each other out, etc.I have successfully abused this feature to install a single router serving multiple areas on a steel ship, with each antenna positioned on the end of a coax run into a different watertight compartment, all separated by steel bulkheads with heavy steel doors. It worked well.