Why RF frequency unstable under CW test?

[steven.zdwang]

We are developing a USB ANT dongle with nRF24AP2-USB chipset, but we meet a problem when use CW test with ATWareII tool.

We set 2.466GHZ, but we see 2.271GHZ mark, but we set 2.466GHz again, we see2.353GHZ mark point set 2.466GHz again, the ouput frequre change to 2.534GHZ. It seems freq is floating, not stable. We use another brand ANT dongle do not meet this issue.

Attached PCB layout and RF mark picture.

We don't why? Could you give us some suggestion? Thank you so much!

pcb_layout.JPG

[steven.zdwang]

Hi Kenneth, I used ANTwareII to do CW test. I found it do ANT_ResetSystem and then do CW test. So I think the ANTWareII CW Test function works fine. The problem root cause maybe in PCB layout, we make this RF production first, could you give us suggestion or checklist for it. Thank you!

Attached ANTWareII CW test function picture.

cw_test.JPG