EC25-EUX minipcie proper LTE antennas

Hi everyone.
I run an EC25-EUX Quectel model and I have some questions on connectivity:

  1. can you please suggest me proper LTE antennas? For the sake of information, I have to say that my Quectel module will be installed inside a waterproof box which will be located inside a metal container. Insidppe the box together with the module, there will be an embedded circuit, of course.
  2. could it be that there are interferences between the antenna and the embedded circuit? where do I have to put the antenna to correctly receive signal?
  3. I’m using the module through pppd interface and I need to raise the connection (pon), transmit and then shutdown the connection with poff. I also shutdown the entire module at the end of this operation, to save energy. At the next transmission, I power the module, make pon, attempt to send data. it seems that the pon procedure is hard (at least 3 modem hangup) and often it does not transmit at all. Am I missing something on using the module?

Thank you

Dear Hyperion,
Thanks for your inquiry in Quectel forum.
Please check the following answers to your questions:
1.About the antenna design, please check the following document. Thanks!
Quectel_Antenna_Design_Note_V3.1.pdf (1.1 MB)
2. It is recommend to follow up the following suggestions to turn off the module.Thanks!

Dear Kyson,
by reading the linked document, I think that Sixfab antennas (like this one, for example, could be fine for the EC25EUX…

Regarding the switch on/off problem, I think that ppp protocol can be shutdown without switching off the module. The problem is yet present even if I do not turn off the module. Actually, even if I do not turn off even the Linux protocol pppd.

It seems that when the module is registered and connected to the network, after 3 seconds it kind of looses the connection and it employs about 15 seconds to ping the same address as before the 3 seconds of waiting…