Hubbel RFL PLC Hybrid Pro, Руководство пользователя

Страница: 21 / 44

RF-MCHYBRIDPRO-01
Hubbell Power Systems, Inc. – RFL™ Products
June 2019 21 973.334.3100
Figure 17 – Skewed Hybrid, Front Panel (test points)
4.4 Splitter
SPL
LINE 1
LINE 2
0 °
IN
180 °
0 °
Figure 18 – Splitter, Functional Diagram
Sometimes called a “balance transformer”, the splitter is used to “split” signals for phase-to-phase
coupling applications (center-phase-to-outer-phase). It is typically installed between the skewed hybrid
and the line tuners – one-line tuner for each phase of the “phase-to-phase” coupling scheme. The 180-
degree phase relationship between the outputs LINE 1 and LINE 2 is required for maximum
propagation down the transmission line in center-phase-to-outer-phase coupling schemes.
This type of hybrid is essentially a balanced hybrid turned around. When balanced hybrids are used,
there is a loss of about 3.5 dB from input to output; when the splitter is measured on the bench, it too
will show a loss of roughly 3.5 dB from “IN” to “LINE 1” and from “IN” to “LINE 2”. However, in
practice the losses are negated, and no loss from the splitter needs to be considered in channel loss
calculations. Conceptually, one can see that the losses due to splitting the signal are recouped when the
signal is then
combined again at the remote end. The real reason that there are no losses is because no
current flows through the balancing termination of the splitter when it is properly applied.