1 Reply Latest reply: Jun 10, 2012 10:22 AM by Harald Naumann RSS

GSM Antenna Placement on Metal Box

Newbie

Hi Guys,

 

Just looking for a little advice on GSM antenna placement on a unit i am working on. The box is made of mild steel and is powder coated. It has a 220V Mains supply at 50Hz going in at the rear also along with a PWM fan,

 

I have attached a drawing of the back of the case in the hope that someone would be able to help me best position it (if its even suitable to go at the back)

 

Plan is to use those small stubby antennas about 50mm in height with a connector on the back to ***** it on to,

 

A few questions really,

 

-  Will the 50Hz mains signal interfere with the GSM Reception??

 

-  Will the 12V PWM Fan interfere with GSM reception??

 

-  Is it ok to place the antenna on the rear of a mild steel powder coated box

 

-  Is it ok that the antenna cant see over the top of the box or will i lose all signal coming from that direction??

 

Thanks again,

 

Stephen

  • Re: GSM Antenna Placement on Metal Box
    Harald Naumann Expert

    -  Will the 50Hz mains signal interfere with the GSM Reception??
    HN: It will not interfere - if you do your job right. Any laptop with embeded GSM modem inside I know is working fine. The world is full with M2M devices close to your description.

     

    -  Will the 12V PWM Fan interfere with GSM reception??
    HN: It will interfere for sure, but the chance on interfere based on a good shielding on your metal enclosure is less. Just make a PCB and test it with your GSM tester like listed here:
    https://plus.google.com/u/0/104073440961325292775/posts/QotyqsfhRfe

     

    -  Is it ok to place the antenna on the rear of a mild steel powder coated box
    HN: Yes, if it a lambda/4 or lambda/2 wave stubby antenna.

     

    -  Is it ok that the antenna cant see over the top of the box or will i lose all signal coming from that direction??
    HN: ??? Sorry but I do not understand the question. A lambda/4 or lambda/2 will radiate omnidirectional as long you to not cover it by metal in the near. The radiation pattern of your antenna you will find in your data sheet.