QPA9122 Higher Than Expected Current Draw

RF Solutions RF Power Amplifiers
1

We are currently using the QPA9122 power amplifier for our design project.

We have followed the schematic on the data sheet and manufactured a board using this design (schematics attached). We are powering VCC at 5V and V_PD at 1.8V. However, we are currently experiencing issues where VCC is drawing around 200 mA, whereas the data sheet indicates it should be closer to 95mA.

Additionally, our S21 gain (tested on a VNA) for RF input power at -20 dBm is approximately 23 dB at 2.4 GHz. Which is also significantly lower than the data sheet specs.

I have attached a picture of our schematic and board layout. Any guidance or insight on this is greatly appreciated. Thank you!

img_schem_layout
img_schem_layout1911×590 216 KB

2

It’s possible that there is some instability. If you bias the device with no RF input are there any spurious signals on the output?
Your layout looks slightly odd as you seem to be transitioning from microstrip with very thin RF tracks to coplanar waveguide with wider tracks. This is going to cause discontinuities and possibly high ground impedances which could cause instability. The decoupling could also be closer to the device. I’d recommend following the Qorvo eval board layout. If you need the eval board gerber files then please e-mail appsupport@qorvo.com stating your company name and location.