Antenna with ground plane?

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AndyGadget
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Antenna with ground plane?

Post by AndyGadget »

I'm trying to increase signal strength to/from a device around 30m away from the router. It's line of sight apart from a (currently bare of leaves) tree, through a double-glazed window. I'm using an ESP32-CAM with standard stick external antenna (I've moved the link :¬) and was wondering whether mounting the antenna on a 6cm diameter aluminium disc as per the image would boost the signal. Reading up on the theory of ground planes, it gets very complex, very quickly and it seems even the knowledgeable people can't agree amongst themselves.
Anyone here into the Black Art of RF theory?

Edit : I've just seen Zim's post here : [Local Link Removed for Guests]
That might be an option as well, although I need to mount the antenna about 10cm above the ESP32 so couldn't use that on the board directly.

Edit : I've just noticed; What the diagram labels 'diameter' is actually the radius!
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Last edited by AndyGadget on Sun Apr 03, 2022 5:08 pm, edited 2 times in total.
bugs
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Re: Antenna with ground plane?

Post by bugs »

Hi Andy,

It's years since I did anything practical with aerials but the ground plane effect just creates a "reflection" of the 1/4 wave whip giving (almost) the benefit of a 1/2 wave dipole.
The 6cm you indicated is not critical, neither is the shape - so just try it with e.g. a sheet of aluminium foil stuck to cardboard. The screen of the coax cable should make contact with the foil.
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Electroguard
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Re: Antenna with ground plane?

Post by Electroguard »

I tried using longer high-gain omni-directional aerials to improve range, also a flat directional plate type, and a long yagi array... but the stronger the signal the less reliable it was - so I ended up just using an additional old router as a wifi extender which could be placed nearer to the target with its original little rubber-ducky.
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Re: Antenna with ground plane?

Post by Zim »

AndyGadget
I am getting a very reliable signal to 120meters with the antenna. I cloned this from a factory router antenna. I am not streaming video, but just sending data with ESPnow.
bugs
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Re: Antenna with ground plane?

Post by bugs »

I suspect an added ground plane might get an extra 3dB of signal at the most - while the energy-saving double glazing could be knocking off about 15->25dB . Easily noted with an Android application on the mobile phone showing wifi signal levels.
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Re: Antenna with ground plane?

Post by PANNO2 »

maybe this is interesting
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Re: Antenna with ground plane?

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