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Pre-emphasis and DE-emphasis circuits?

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Advanced Member level 4
May 17, 2002
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pre emphasis circuit

what is Pre-emphasis and DE-emphasis circuits in FM voice radio?

what is do?

Please send information.


Pre-emphasis shapes a signal before it is sent and post-emphasis shapes it after it is received. The idea is to compensate for distortions that the transmission channel may/will introduce.

Radars also sometimes use this to spread a pulse and thus transmit more power. Then on reception compress the pulse to improve range resolution. pre-emphasis

please give me some OPAMP circuit for pre-emphasis and de-emphasis.

pre emphasis and de emphasis

Deemphasis circuit is trivial. Use current generator which supply parallel RC whose time constant is 50us or 75us regarding what you need.

any idea on matlab source code of this pre-emphasis FIR filter?

I have 1 coding in my hand but the number of order is too high!!! i doesnt want the number of order higher than 32.

Any idea?

Re: pre emphasis and de emphasis

[I need pre emphasis and de emphasis circuits using opamp

Re: pre emphasis and de emphasis

[I need pre emphasis and de emphasis circuits using opamp

dear you all

in PCIe gen 3, why do we need preshoot technique ?

thank you in advance

Since noise is constant per unit bandwidth , noise is thus greater with higher center frequency
i.e. bass 50 ~500Hz is lower bandwidth than 500~15kHz so the treble is amplified on transmitter and reduced in receiver so response net is flat.

I recall there is 15dB of pre-emphasis but I forget the breakpoint frequency.

dear sunny ?
could you explain more about preshoot in detail ?

visualize treble control set to 15dB gain for Transmitter (Tx) and Receiver treble set to -15 dB before the equalizer.

This is pre-emphasis..(Tx) and de-emphasis (Rx)

not preshoot.

i think there is a different view of PRESHOOT.
this is its definition :
" Preshoot is a new feature designed to improve the signal in the following bit time by boosting the voltage in the current bit time"

why it can improve signal ?


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