IWR6843ISK: z-axis data is higher than actual position

Hi,

I tested detection performance with OOB demo FW(SDK 3.5) using IWR6843ISK.

The test environment is as follows.

and configuration is below.

sensorStop
flushCfg
dfeDataOutputMode 1
channelCfg 15 7 0
adcCfg 2 1
adcbufCfg -1 0 1 1 1
profileCfg 0 60 10 7 49.1 0 0 50 1 512 12499 0 0 158
chirpCfg 0 0 0 0 0 0 0 1
chirpCfg 1 1 0 0 0 0 0 4
chirpCfg 2 2 0 0 0 0 0 2
frameCfg 0 2 16 0 100 1 0
lowPower 0 0
guiMonitor -1 1 1 1 0 0 1
cfarCfg -1 0 2 8 4 3 0 15 0
cfarCfg -1 1 0 4 2 3 1 15 1
multiObjBeamForming -1 1 0.5
clutterRemoval -1 0
calibDcRangeSig -1 0 -5 8 256
extendedMaxVelocity -1 0
bpmCfg -1 0 0 1
lvdsStreamCfg -1 0 0 0
compRangeBiasAndRxChanPhase 0.0 1 0 1 0 1 0 1 0 1 0 1 0 1 0 1 0 1 0 1 0 1 0 1 0
measureRangeBiasAndRxChanPhase 0 1.5 0.2
CQRxSatMonitor 0 3 5 101 0
CQSigImgMonitor 0 127 8
analogMonitor 0 0
aoaFovCfg -1 -90 90 -90 90
cfarFovCfg -1 0 0.6 30
cfarFovCfg -1 1 -1 1.00
calibData 0 0 0
sensorStart

The coordinates of the detected cloud point are [0.6, 20.85, 4.76]

I haven't tried RX channel gain/phase compensation yet, but I think the error is too big in z-axis.

An error of 4.7m is calculated as an error of about 13 degrees.

I will buy soon corner reflector for RX channel gain/phase compensation, but are there any considerations other than phase error? 

Thanks.