ESP8266 Community Forum

- Mon Oct 10, 2016 6:36 am #56314 Hi guys,

I made a nice PCB for data logging that's very small with just an ESP-07 and a battery directly behind it.
Unfortunately.. The range is not very good.

I think this could be cause by two things:
1. Horizontal chip antenna (due to donut shape of signal transmission)
2. Battery behind the antenna

I'm thinking about how to improve this but need some expert comments!

This is the design:


Red = ESP-07
Blue = horizontal chip antenna

What is the best option?
1. Change to ESP-08 module and move antenna vertical and to the side of the PCB
2. Change to ESP-12 so that the transmission of the signal is more optimal for this placement on the PCB

- Tue Oct 11, 2016 7:47 am #56362 Keep the area above the antenna clear of metal, in all directions.

https://espressif.com/sites/default/fil ... uide_0.pdf

- Tue Oct 11, 2016 9:48 am #56373 Thank you for the pdf.

Unfortunately, I do not have the luxury to place it away from metal and therefore I am looking for the least worse solution. The pdf is also not talking about the chip antenna.

Horizontal placement of the chip antenna gives a bad range. The distance between the chip antenna and the battery is about 4mm.

I can place the chip antenna vertically and move it to the side of the PCB. Will this improve range? ie. will the radiation pattern be more optimal?

Another option would be the use of the meander PCB antenna. But the document is not discussing the required distance in the Z-direction.

- Tue Oct 11, 2016 12:37 pm #56380 If you can live with poor performance behind it (due to the battery) then maybe you can use the battery as a reflector. The spacing between the antenna and the reflector has to be worked out. My antenna theory knowledge is pretty rusty so you would need to do a search on it.