# QM33120WDK1 PDoA angle value is faulty

## how does QM33120WDK1 PDoA calculation work?

It will be very helpful to explain based on the code.
I am using the code below.

• Documents > [QM33 DK Software, Sources, Tools and Developer Guide]

Project Directory : QM33 DK Software, Sources, Tools and Developer Guide/QM33120WDK1/DW3_QM33_SDK/Sources/nRF52840DK-DW3_QM33_SDK-FreeRTOS_DW3_QM33_SDK_0_1_1/nRF52840DK-DW3_QM33_SDK-FreeRTOS/Projects/DW3_QM33_SDK/FreeRTOS/nRF52840DK/sesnRF52840DK-DW3_QM33_SDK_CLI-FreeRTOS.emProject

p.s. AoA angle result looks okay.

p.s. AoA angle result looks okay except at +90 degree which is the situation placing the tag at the right.
It will be very thankful if someone can explain this too.

Hello,

Can you help us understand why you think the “PDoA angle value is faulty”?

Here is a video from FiRa that explains how AoA works from PDoA: https://www.youtube.com/watch?v=5k938MZiHXY

Essentially there is a look-up table (LuT) which converts the PDoA to AoA. This LuT is unique for each antenna depending on the antenna element spacing and properties.

+90 degrees angle is at the area where we would expect PDoA wrapping and aliasing. At this angle, the PDoA value might be around +180 which is aliased to -180 and therefore, we cannot discern if the measurement is coming from +90 or -90 and hence, you have nearly the same results in your +90 and -90 angles.

Generally, the field of view where we have good results is around +/- 60 degrees as the PDoA to AoA curve is not linear but rather more like a sigmoid.

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