User's Manual

Doc. No.
Rev.
Date
1.00
2011-12-08
Damm Cellular Systems A/S, Denmark
TETRAFLEX
®
V7.5 MANUAL - TX Combiner for BS41x
TetraFlex® 7.5 Manual 4-10
The schematics of the cavity combining system are shown below:
4.2.2.1 Circulator
The TX output signals come from the TR41x to the TC411 in cables attached to the
Cassettes. In the TC411 it first passes a dual circulator, which gives a reverse isolation of at
least 50dB.
A circulator is a very special device with different insertion loss in the two directions. It is a
passive but non-linear device, which do not follow Ohm’s law.
A circulator is a 3-port device, which behaves as a turn-around with the rule, that when you
enter a port you follow the direction of the arrow around and leave the first-coming outlet
again.
The function of a dual circulator is shown on the drawing below: