Nortel DualMode 800, Руководство по обслуживанию

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Antenna return loss 6-3
Wireless Solutions DualMode 800 Enclosure Maintenance Manual MTX08
Figure 6-1
Antenna return loss block diagram
Step Action Observation
1 Connect the signal generator, the spectrum
analyzer and a 50 ohm load to the VSWR
bridge. See Figure 6-1.
2 Set the signal generator output level to 0
dBm.
3 With the device under test (DUT) VSWR
bridge port connected to an open, adjust the
display on the spectrum analyzer to the top
of the screen.
4 Connect a 50 ohm termination to the open
port on the VSWR bridge and step the
generator through the receive and transmit
band to verify the test set-up for return loss. Return loss should be greater than 35 dB
over the bands.
5 Remove the termination from the VSWR
bridge, connect the antenna jumper cable to
the open port and again step the generator
across the transmit and receive bands.
6 Record the minimum return loss of the
antenna and transmission line in the system. Return loss:824 to 849 MHz RX
869 to 894 MHz TX
Greater than or equal to
14.5 dB + (2 x TX line loss)
7 Repeat the test for each antenna installed for
the cell site.
8 If the test fails, check the antenna matching,
cables and connectors.