QUESTION

Question

Hi everyone!

I'm testing the original SR44G053 Raptor antenna evaluation board. I designed a separate module of L1+L2+L5 amplifier mentioned in my previous post. 

I want to move from the prototyping stage to designing a final product, Raptor integrated with a triple band amplifier on a single PCB.

1. I'd like to shield the RF amp with this: https://www.harwin.com/products/S03-30100300/ 

Is it ok if I place it on the top layer so the same plane as the antenna? I think I should avoid switching planes (routing signal to bottom layer). If it's unavoidable (the shield has to be on the bottom of the PCB) what's the best way to transfer the RF signal from top to bottom? I was thinking of using a short u.fl to u.fl pigtail but I'd like to hear the experts' opinion.

2. For the product I was going to use the original evaluation board dimensions but before I do so, I'd like to know whether making the ground plane bigger can help me achieve even better overall performance? If it matters the antenna will be used on a fixed-wing UAV traveling around 12m/s.

Answer 1

Hi,

1. The shield should be far away from the antenna, but it is OK that the shield is on the same side as the antenna.  It is not necessary to have a cable to connect top and bottom of the PCB. A via will not reduce the signal strength at GNSS frequencies.

2. Increasing the ground plane size will not give a significant improvement in performance.

Best regards,

Yu Kai Yeung