I purchased a 3G dongle from an unknown manufacturer (ZD Incorporated), and I am trying to boost its signal with a 3G antenna. I'm on the assumption that the manufacturer did not put an antenna there, but it's possible to solder one, because I've seen exactly the same model but with an external connector (more expensive). The only known information is that uses a Qualcomm chip.

Here is the antenna:

ZD Incorporated 3G Dongle

I have bought an UFL connector in order to solder to the PCB, but I do not find the standard placement (2 ground connectors and 1 signal), so I cannot really decide where to solder it.

Any suggestion or experience with this devices? Is this even possible?

Edited (@PeterJ): Here it is a zoomed image:

Bottom image: bottom-left

  • \$\begingroup\$ It's a bit hard to tell from the photo but I'd guess that second PCB (at the left in the bottom image) is an antenna. Can you spot how that seems to be connected to the main PCB? \$\endgroup\$ – PeterJ Feb 20 '14 at 11:43
  • \$\begingroup\$ Yes, I guess it should be some of these. The leftmost component is connected by a thin wire as you can see. On the other side of the PCB there are no connections for this component. The rightmost part of the image is just onto the SIM card reader. But there are no visible connections. \$\endgroup\$ – fmoralesalcaide Feb 20 '14 at 12:39

It appears that the two parallel strips of solder are for mounting the shield to a connector and there is a small component in series with the signal passing to the left into the small red brick. My answer is conjecture and comes without warranty of functionality as it requires removing at least one component from your device.

enter image description here Red: what looks like the current antenna.

Dark blue: approximate position of connector.

Light blue: SMD component that would be in the way of the connector's center pin.

Additionally, note that your device has solder pads for metal shields over its RF components on each side, but those shields were not placed during manufacturing.

  • \$\begingroup\$ So, if I understand your conjecture, I should try removing both the current antenna and the light SMD connector, and then solder the UFL where the solder pads suggest. The UFL dimensions match exactly that placement, and the solder pads suggest to solder there. I will give it a try and post the results. Thank you so much! :) \$\endgroup\$ – fmoralesalcaide Feb 20 '14 at 16:12
  • \$\begingroup\$ You're welcome. Please accept the answer if it works out. Good luck! \$\endgroup\$ – user2943160 Feb 20 '14 at 17:51

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