User Manual

Table Of Contents
INSTALLATION GUIDE
Proprietary Information
Title: BEAMER Array System-
Assembly and Operation Manual
Doc. No.: 913000100 Rev.: 00
Page: 55 of 92
2.10. Test Procedure for Measuring the Rx Gain Balance
This section describes a way to measure the gain difference between to RF front-end channel.
Following the installation of a Pol. BEAMER array.
The measurement requires test equipment and somewhat involved test set-up, based on mobile RF
signal generator connected to an antenna, capable of rotating on the horizontal plane. This test setup is
not always available. Moreover, the good balance between the BEAMER gain blocks, on both the
BEAMER -Rx modules and the ICU, guarantees the gain balance.
However, we suggest to perform this measurement to one or two selected sites, as part of the system
validation tests.
1. Place a signal generator with an omni-directional antenna, at a distance of 50-100meters from
the array. The antenna should be mounted as a vertically polarized antenna.
2. Tune the signal generator output to Rx Center frequency, output power of 0dBm.
3. Connect a spectrum analyzer to the ICU's Rx-ABT output for Rx1 channel. Tune the spectrum
analyzer to Rx Center frequency, zero span, RBW=30kHz, reference level =-20dBm@5dB/div,
sweep time = 10Seconds.
4. While constantly moving the transmitting antenna on the horizontal plane, without altering the
polarization direction, watch the spectrum analyzer display of the received CW carrier. (you
can use a rotating plate or move the antenna manually).The spectrum analyzer display will
show a varying level line, around ~-30dBm. Estimate the average level of this line, Pr1, to
±1dBm.
Time
Power
Estimated average level
Recorded trace
Figure 23:Measuring the received
1. Repeat for the other Rx-ABT output, for Rx2 receiver, to get Pr2.
2. The readings for Pr1 and Pr2 should match to ±2dB. You can compensate up to ±4dB by fine-
tuning the Rx-ABT gain (available gain step is 0.5dB). It is recommended to increase the gain
of one Rx-ABT and to reduce the gain of the other, to minimize the effects of possible over- or
under-gain conditions. If Pr1 and Pr2 differ within more than ±5dB, it might indicate an
installation problem.