Comtech EF Data KST-2000L - Manual (Page 45)

Satellite Terminal System Revision 2
Operation MN/KST2000L.IOM
72 MHZ
REF
L03
16.830
GHZ
13.750 to
14.500 GHZ
2330-
3080 MHZ
Figure 4-4. S to Ku-Band Up Converter Module
The S to Ku-Band up converter module (Figure 4-4) performs block up conversion of the
2,330 to 3,080 MHz signal input to an output in the range of 13.750 to 14.500 GHz. This
is done by mixing the IF input with a fixed frequency Dielectric Resonator Oscillator
(DRO), operating at 16.830 GHz. The correct sideband of this process is amplified and
filtered before being applied to the isolated output of the module.
4.4 L-Band to IF Down Converter Description
The L-Band to IF down converter (Figure 4-5) accepts an RF input in the frequency
range of 950 to 1,700 MHz and translates it to an output of 70 (140) MHz. The RF input
to this module is supplied from an externally mounted LNB.
950-1700
MHZ
From LNB
72 MHZ
REF
70/140
MHZ
720 (70)
790 (140) 1.6-2.35
GHZ
0-20 dB STEP
ATTENUATOR
INTERFACE
L-BAND
MONITOR
Figure 4-5. Ku-Band to IF Down Converter Block Diagram
The 950 to 1,700 MHz input is first pre-selected and then heterodyned with a local oscil-
lator in the range of 1.6 to 2.35 GHz to generate the first IF signal of 650 MHz. The 650
MHz signal is then mixed with 790 or 720 MHz to generate the 70 or 140 MHz output.
The IF output frequency of the second down conversion stage is then amplified and ap-
plied to a 0 to 20 dB step attenuator with 1 dB steps. The overall Ku-Band down con-
verter tunes in a frequency step-size of 1 MHz across the 950 to 1700 MHz band.
This module is slightly different for the 70 and 140 MHz options.
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