- This topic has 8 replies, 1 voice, and was last updated 10 years, 2 months ago by anshu.
9th August 2006 at 09:58 #45564MichaelGuest
I’m presently working on a project that require a deeper understanding of the workings of combiners especially Filter and Hybrid.
information concerning the characteristics and advantages of one combiner over another is desired.
thanks10th August 2006 at 07:05 #45565PavelGuest
I have good E/// document about combiner solutions with CDU-G for RBS2000. If u are interested – I can send it to your via e-mail(~200 Kb in rar).10th August 2006 at 14:23 #45566PavelGuest
Combiners are needed to enable more than one transmitter to be
connected to one common transmitting antenna. Without a
combiner the output from one transmitter would loop back into
the output of another since both of them are physically
connected to the same antenna.
In GSM, two different TX-combiners can be used: filter and
hybrid.10th August 2006 at 14:23 #45567PavelGuest
The filter combiner can combine the output of up
to eight transmitters. In order to use nine to sixteen transmitters
in a cell, two filter combiners and two antennas must be used. It
is a narrow band combiner where the frequency of each of the
connected transmitters (TRXs) must be tuned by adjusting a
filter. This is done automatically by the system but nevertheless
takes some time.
The total loss in a filter combiner is around 3-4 dB.
The combiner output is connected to the transmitting antenna on
top of the cabinet via a Measuring Coupling Unit (MCU) and a
bandpass filter TXBP.
The transmitter divider (TXD) distributes the loopback signal
from the MCU to the different transmitters to enable automatic
tuning of the filters in the combiner. It also enables Voltage-
Standing-Wave Ratio measurements (VSWR).10th August 2006 at 14:40 #45568MichaelGuest
The filter combiner i’m used to ( CDU-F) can only combine a maximum of 4 transmiters, is their any enhancement?.My email is email@example.com, i’ll be glad to receive the available document10th August 2006 at 14:54 #45569PavelGuest
CDU-G can combine 4 TRX maximum also.
Unfortunately I don’t remember what is deifference between CDU-G and CDU-F 🙁 If i shall find – im going to post it here.10th August 2006 at 14:58 #45570PavelGuest
The only info I have:
• CDU-F is a filter combiner intended for high capacity solutions.
• CDU-G can be configured either for high capacity or for high coverage. It is
a combiner that can be used for synthesizer hopping.4th February 2011 at 12:16 #45571dGuest
Pavel, COULD YOU SEND E/// document about combiner solutions with CDU-G for RBS2000 TO firstname.lastname@example.org ?4th February 2011 at 13:01 #45572anshuGuest
Pavel if possible then plz send me also