Cable Equalizer Filter; Figure 74: Example Of Non-Linearity In A Rg188A/U Cable - Safran CORTEX Series User Manual

3.7

Cable equalizer filter

The purpose of the optional cable equalizer filter is to compensate for cable degradation by means of
a digital equalizer integrated to the receiver. Analog equalizers are commonly used to solve this
problem; however a digital implementation offers the following advantages:
 More flexibility,
 Higher performances.
The primary cause of transmission loss below 1 GHz is skin effect, which is proportional to the square
root of frequency:
Since this type of non-linearity is almost linear between 500 MHz and 1 GHz (above figure), it can be
well compensated by a straight line with opposite rope of the tangent.
The sampled signal is filtered before baseband transposition. By this way, a symmetrical low-pass filter
can be implemented:
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HIGH DATA RATE RECEIVER
HDR-4G+ USER'S MANUAL
Amplitude Loss
(dB)

Figure 74: Example of Non-linearity in a RG188A/U Cable

It cannot be duplicated or distributed without expressed written consent.
Ref. DTU 100782
Is.Rev
Date:
= A * sqrt (frequency)
Safran Data Systems
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