Quick Installation Guide
Document
WERA4-Quick-US-200917
Page 41 of 73
When all cables are in their final position and connected to the Splitter the final tuning
starts:
1. Connect the already tuned antenna to the antenna meter and check the tuning.
Most likely it has changed and a re-tuning is required.
2. Reconnect the first antenna to the Splitter to ensure a correct load and proceed to
the next antenna for tuning.
3. Reconnect the second antenna to the Splitter and proceed with the next antenna.
4. Reconnect the third antenna to the Splitter and proceed with the last antenna.
5. Now reconnect the last antenna to the Splitter and check the first one again. Most
likely it has changed and a re-tuning is required.
6. Repeat the entire cycle until the result is ok.
The VSWR of the Tx antennas is critical and should be almost identical for all 4 Tx
antennas. The resonance dip (if it is sharp) should be outside the sweep bandwidth. The
VSWR value should be lower than 1:1.6 (in worst case 1:2).
Finally when all 4 Tx are well tuned and connected to the 1:4 Splitter the performance
should be checked:
Use the identical WERA settings as before at the beginning of this chapter.
Start a
Calibration
under the WERA Control Centre. Use settings for a short run:
256 samples, 0.260 sec sweep time, 80 Hz offset
Check the results using “Plott_WERA_Cal_lsq
”
according to the description in pos. 11.7.
Write down the
rms voltage
of the antenna closest to the Tx array in the “Installation
Check List” in the line below the value measured with one Tx antenna only. This new value
must be lower than the value measured before.
The ratio between the first measured voltage and this new one should be better than
3 the best case is about 10.
If not the Tx array is radiating in a wrong direction or rf power is directed through a metal
fence towards the Rx array or it is reflected from a metal construction nearby.
Now Start a
Single Acquisition
, don’t forget to set the frequency offset to 0Hz
512 samples, 0.260 sec sweep, no frequency offset
C
heck the results using “Plott_WERA_Sort_RCs_Beam_rfi
”
according to the description
in pos. 11.5.
From the Range Doppler plot the range can be estimated. Please write down this
estimated range at 0° in the “Installation Check List” below the before measured value.
The range should be longer now.
If not the Tx array is radiating backwards or the environmental conditions have strongly
changed since the first acquisition.
Now the Tx array should be ok.
