Signal drop when using BLE module on custom PCB

RE: Signal drop when using BLE module on custom PCB

devops — Wed, 05 Dec 2018 13:05:39 GMT

I manually removed the area under the antenna on the PCB and the signal gain was +20...+30dBm.

I will look upon these keywords that you provided, thank you again!

RE: Signal drop when using BLE module on custom PCB

haakonsh — Wed, 05 Dec 2018 12:54:27 GMT

Not any one in particular, but a searchable keyword is '2.4GHz antenna design' and '2.4GHz printed antenna design'. The type of antenna that your module uses is a printed quarter wave meandering antenna.

Another slightly related topic is 'microstrip' and 'stripline'.

RE: Signal drop when using BLE module on custom PCB

devops — Wed, 05 Dec 2018 12:12:25 GMT

Thank you for your answer. Do you know a good source from where I could follow up on this? An article or such.

RE: Signal drop when using BLE module on custom PCB

haakonsh — Wed, 05 Dec 2018 11:59:43 GMT

The module's datasheet does not specify layout at all, this one's on the module vendor. http://aconno.de/wp-content/uploads/2016/10/ACN52832-Data-Sheet.pdf

RE: Signal drop when using BLE module on custom PCB

haakonsh — Wed, 05 Dec 2018 11:55:59 GMT

You need to remove the GND plane under the antenna:

You must also remove the copper from the two mounting holes and only use plastic mounting screws.
Any metal, water, or other 2.4GHz opaque materials will affect the antenna negatively.

RE: Signal drop when using BLE module on custom PCB

awneil — Wed, 05 Dec 2018 11:09:27 GMT

The module's documentation should have details about PCB requirements - in particular, "keep-out" areas and ground planes ...