User's Manual

P B L Tunnel Units 1 & 2
Maintenance Handbook
H/book Number:-60-056100HBKMFCC
Issue No:-2
Date:-04/01/2006
Page:-
27 of 63
5.2.3 Crossband Couplers (07-004801 & 07-005705)
5.2.3.1 Description
The purpose of a crossband coupler is to either combine/split transmission signals from
different parts of the frequency spectrum.
The crossband coupler fitted here, is the means by which the separate UHF & GSM
frequency band signals are mixed to form a composite RF signal.
It basically comprises of a 3 port device, two filters, one a low pass the other a high pass, that
are then mixed and fed to a common output. The couplers are built into a machined
aluminium casing having a centre screening wall between the filter sections and lid secured
by screws at frequent intervals over its perimeter to obtain a tight seal and to ensure linearity
and stability of response.
5.2.3.2 Technical Specification (07-004801)
PARAMETER SPECIFICATION
390-490MHz
Passband:
700-900MHz
N. Of i/p ports: 2
N. Of o/p ports: 1
Insertion loss: 0.5dB (typical)
>40dB 390-490MHz
Isolation:
>40dB 700-900MHz
Impedance: 50Ω
Connectors: SMA female
Power rating: 50Watts (CW)
5.2.3.3 Technical Specification
PARAMETER SPECIFICATION
250 MHz
Passband:
380 MHz
70.0-250MHz
380-960MHz
Power Rating 50 Watts (CW)
Number of Input ports 2
Number of Output ports 1
Insertion loss 0.5 dB
Isolation > 50 dB 70-250 MHz
> 50 dB 380-960 MHz
(15 dB typical return loss 500-960)
Impedance 50 
Connectors SMA- female