QUESTION

Question

Hello,

My question relates to the Antenova M20057. In my application I require the PCB, which the antenna will be mounted on, to be in direct contact with a Aluminium cylinder. This violates the requirement of no ground or tracks to be placed below the antenna, as this cylinder will be on the bottom of the PCB with the antenna on the top. It is possible to offset the antenna so it isn't centered, however this then decreases the ground planes on either side. Offsetting the antenna will increase the distance between it and the Aluminium cylinder.

My question relates to the trade-off between the two. Would the performance of the antenna be worse off centered (but very close to a metallic object ~0.8mm, PCB thickness) or offset (~10mm from the edge of the PCB, but ~1.9mm - ~3mm off the metallic object)?

Kind regards,
William

Answer 1

Hi William,

Will the cylinder be the antennas source for the ground return of the antenna? The reason I ask is because pads AT1 and AT2 require a ground connection in order for the antenna to work. Assuming that our module is placed on the appropriate size PCB and that the cylinder is just a floating metallic object in space then it would be best to shift the module so that the cylinder comes closer to one side of the opening or the other rather than centered directly in the middle of the antenna's keep out area.

Best regards,

Geoff S.