one question about NDT

[William.wei]

hi support team,

we can see the slide in this link：/cfs-file/__key/communityserver-discussions-components-files/4/3201.Measuring_5F00_distance_5F00_with_5F00_Nordic_5F00_Distance_5F00_Toolbox_5F00_slides.pdf

it is clear:

λ2.440GHz = speed/frequency = 3.0e8 m/s / 2.440 GHz = 0.123 m

for 2 meters round trip 2/0.123= 16.26  and the remainder is 0.26*2π.

may i ask where the phase slope comes from? what does it mean?

Regards,

WIlliam.

[PaKa]

The phase slope is the remainder plotted for all frequencies in a ranging. This is in radians. The slope of the curve gives you the distance, as you can see the slope for the longer distance is steeper than the one for the shorter distance.

[William.wei]

Hi Paka,

let me guess why the phase slope value is more than 2π.

for 2.69 meters distance example,

2.69*2 /0.125= 43.04  and the remainder is 0.04*2π.

2.69*2/0.121 = 44.46, and the remainder is 1.46*2π. the remainder is not 0.46*2π.

am i right?

Regards,

William.

[PaKa]

Yes, if you limit the output to +/-3.14 radians then you will get multiple segments with a 6.28 "jump" between them so to highlight this is a line the figures use the lowest frequency as the base and all phase changes are plotted against that.

[William.wei]

Thanks Paka,

Really thanks.

Another question is what's the difference between the iq value of NDT and the iq value of AOA/AOD.

what's the difference if they are different?

Regards,

William.