PSR78 Repeater
User Manual V0.1
Page | 2
3.5.4 Antenna Separation/Isolation
Separation between the antennas is necessary to prevent oscillation. Oscillation occurs when the signal entering the
system continually reenters, due to the lack of separation between the donor and server antennas. In other words,
the signal is being fed back into the system. This creates a constant amplification of the same signal. As a result,
the noise level rises above the signal level.
REPEATER
Figure 9: RF Repeater Oscillation
To prevent feedback, the donor and server antennas must be separated by an appropriate distance to provide
sufficient isolation. Isolation is attained by separating antennas a sufficient distance so that the output of one
antenna does not reach the input of the other. This distance is dependent on the gain of the repeater.
A sufficient isolation value is 13 ~ 15 dB greater than the maximum gain of the repeater. For example, if the gain of
the repeater is 50 dB, then an isolation of 63 ~ 65 dB or greater is required. In the same manner, because the
PSR78 has a maximum gain of 90 dB, it requires an isolation of at least 103 ~ 105 dB.
Содержание PSR78
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Страница 25: ...PSR78 Repeater User Manual V0 1 Page 11 4 4 Install Tab 4 4 1 Install 700MHz 800 MHz ...
Страница 36: ...PSR78 Repeater User Manual V0 1 Page 22 Appendix A Mechanical Drawing Figure 7 PSR78 mechanical drawing ...
