Cascading LNAs using TQP3M9009 may meet some oscillation problem

Wireless Connectivity Ultra-Wideband
1

Hi Qorvo teams,

I am using a cascade LNAs TQP3M9009 with single power supply +5Vdc.
And I met a oscillation problem now.
I measured the cascading output, there is a harmonic around 350MHz and 700MHz.
Below attached the schematic and PCB layout.
I did use a solid ground plane beneath the LNAs.

image
image1648×566 58.6 KB

I use a spectrum analyzer to the 2nd-stage output, there is a oscillation at 350MHz and 700MHz.

I need HELP about this issue.
Thank you so much.

SK.

2

BTW, C73 is actually installed a 0 ohm resistor.

3

Hi @SKWen
Just to double check, you want to use two PA for DW1000?

Cheers
JK