Radio Solutions Inc SB800M2A 사용자 설명서
© 2016 Radio Solutions, Inc. Norwell, MA - USA
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1. Design the Distributed Antenna System (D.A.S) – Design the D.A.S for optimal
signal coverage of the building or other confined area. The D.A.S. system can be designed
by using a combination of radiating cable, non-radiating cable, antennas, signal taps,
splitters or hybrid couplers. To prevent feedback oscillations, a solid outer conductor, non-
radiating cable must be used to connect the booster to the D.A.S. and donor antenna
systems. If high gain antennas are used, it is important to limit the output power of the
signal booster so that the maximum ERP does not exceed the 5W limit (see the warning and
calculation instructions on page 2).
signal coverage of the building or other confined area. The D.A.S. system can be designed
by using a combination of radiating cable, non-radiating cable, antennas, signal taps,
splitters or hybrid couplers. To prevent feedback oscillations, a solid outer conductor, non-
radiating cable must be used to connect the booster to the D.A.S. and donor antenna
systems. If high gain antennas are used, it is important to limit the output power of the
signal booster so that the maximum ERP does not exceed the 5W limit (see the warning and
calculation instructions on page 2).
2. Locate the Donor Antenna – The Donor antenna should be a high-gain, directional
type antenna and should be aimed at the nearest radio system repeater site. Location of the
antenna should be chosen so that it provides highest possible signal isolation from the
D.A.S. system. It is important to limit the output power of the signal booster so that the
maximum ERP does not exceed the 5W limit (see the warning and calculation instructions
on page 2).
type antenna and should be aimed at the nearest radio system repeater site. Location of the
antenna should be chosen so that it provides highest possible signal isolation from the
D.A.S. system. It is important to limit the output power of the signal booster so that the
maximum ERP does not exceed the 5W limit (see the warning and calculation instructions
on page 2).
3. Measure the D.A.S. to Donor Antenna Signal Isolation – Probably the most
important step in design and deployment of an in-building signal booster system is to
ensure that there is a sufficient signal isolation between the donor antenna and the D.A.S.
system. Just like the feedback that occurs when the microphone and speaker get too close
together on a public address system, a signal booster can start to oscillate when the gain of
the system is higher than the isolation of the antenna system. The oscillations can cause
continuous in-band interference to other users that are in the range of the signal booster.
To prevent the feedback oscillation from happening it is important to ensure that the
amount of antenna isolation is at least 15dB higher than the signal booster gain. Antenna
isolation is measured by generating a test signal into the D.A.S. system and measuring the
level of the signal received off the donor antenna using a spectrum analyzer or other device
capable of accurately measuring RF signal levels. If a directional hybrid couplers are used in
the D.A.S. system then the same test should be performed in other direction by generating
the test signal into donor antenna and measuring the received signal level from the D.A.S.
system. Once the signal separation is measured, deduct 15dB from the figure and the result
is the maximum amount of gain that is allowed.
important step in design and deployment of an in-building signal booster system is to
ensure that there is a sufficient signal isolation between the donor antenna and the D.A.S.
system. Just like the feedback that occurs when the microphone and speaker get too close
together on a public address system, a signal booster can start to oscillate when the gain of
the system is higher than the isolation of the antenna system. The oscillations can cause
continuous in-band interference to other users that are in the range of the signal booster.
To prevent the feedback oscillation from happening it is important to ensure that the
amount of antenna isolation is at least 15dB higher than the signal booster gain. Antenna
isolation is measured by generating a test signal into the D.A.S. system and measuring the
level of the signal received off the donor antenna using a spectrum analyzer or other device
capable of accurately measuring RF signal levels. If a directional hybrid couplers are used in
the D.A.S. system then the same test should be performed in other direction by generating
the test signal into donor antenna and measuring the received signal level from the D.A.S.
system. Once the signal separation is measured, deduct 15dB from the figure and the result
is the maximum amount of gain that is allowed.
Example:
Test Signal Level generated into the D.A.S. system: 0dBm
Measured Test Signal Level at the Donor Antenna: -70dBm
Signal Isolation = 0dBm – 70dBm = 70dB
Maximum Booster Gain Allowed: 70dB -15 = 55dB