Safran CORTEX CRT Quantum - Input Frequency; Table 32: Examples of Downlink Converter Setup with

COMMAND RANGING & TELEMETRY UNIT CORTEX
CRT QUANTUM USER'S MANUAL
Ref. DTU 100042
Is.Rev. 5.17
Date: Dec.
03, 2021Sept. 30, 2021
© Safran Data Systems
This document is the property of Safran Data Systems.
It cannot be duplicated or distributed without expressed written consent.
Page 210
3.8.1.1. Input Frequency
The frequency domain can be:
 60 to 78 MHz for IF legacy operation. In this case, the EFC programs automatically the bypass
function
 930 to 2400 MHz for L/S-Band Operation.
Important Note
Please note that,
 To obtain an accurate base-band transposition of the RF signal, there are two parameters to be set:
 The RF converter frequency (with 5MHz step*) for down conversion L/S band to the intermediate
band
 The Input frequency of the IF Receiver (with an accuracy of the Microhertz) for the down conversion
intermediate band to base band
The IF frequency shall be adapted accordingly to the RF frequency.
The formulas given the RF converter frequency and the IF frequency are:
EFC converter frequency = the multiple of 5MHz nearest to the RF input frequency
IF frequency = 70MHz + (RF input frequency – EFC converter frequency)
*Remark: The local oscillator used on the EFC board has been chosen to guarantee a good phase noise. In
return the frequency step of the oscillator is 5 MHz.
Here below some examples of downlink conversion setup:
RF input
signal
frequency
EFC converter
frequency
IF signal frequency
IFR input
frequency
975 MHz
975 MHz
70 + (975 – 975) = 70 MHz
70 MHz
975,1 MHz
975 MHz
70 + (975,1 – 975) = 70,1 MHz
70,1 MHz
2203,5 MHz
2205 MHz
70 + (2203,5 – 2205) = 68,5 MHz
68,5 MHz
Table 32: Examples of downlink converter setup with EFC