Method for manufacturing a transmission line equalizer

• US 20090183362A1
• Filed: 01/18/2008
• Published: 07/23/2009
• Est. Priority Date: 01/18/2008
• Status: Active Grant

• Current Assignee: Inventec Corporation
• Original Assignee: Inventec Corporation
• Inventors: Chu, Cheng-Hui
• Granted Patent: US 7,703,202 B2
• Time in Patent Office: Days
• US Class Current: 29/825
• CPC Class Codes: H04L 25/03878 Line equalisers; line build-out devices
• CPC Class Codes: Y10T 29/49004 including measuring or testing of device or component part
• CPC Class Codes: Y10T 29/4902 Electromagnet, transformer or inductor
• CPC Class Codes: Y10T 29/49082 Resistor making
• CPC Class Codes: Y10T 29/49117 Conductor or circuit manufacturing
• CPC Class Codes: Y10T 29/49155 Manufacturing circuit on or in base

Abstract

A method for manufacturing an equalizer used to compensate a digital signal passed by a transmission line, in which the digital signal can be presented as a frequency-domain function. The method includes measuring a the transmission line scattering-parameter; performing an integration and a differentiation about the transmission line scattering-parameter, the frequency-domain function, the ideal gain, and an equalizer scattering-parameter to get the component impedances of the equalizer; and manufacturing the equalizer circuit with the derived component impedances.

Claims

1. A method for manufacturing an equalizer used to compensate a digital signal passed by a transmission line, wherein the digital signal can be presented as a frequency-domain function, the method comprising:

measuring a the transmission line scattering-parameter;

performing an integration and a differentiation about the transmission line scattering-parameter, the frequency-domain function, an ideal gain, and an equalizer scattering-parameter to get the component impedances of the equalizer; and

manufacturing the equalizer circuit with the derived component impedances.

2. The method as claimed in claim 1, wherein the equalizer comprises an inductor and a resistor in series connection, and the equalizer scattering-parameter is

$H_{\mathrm{equalizer}}$

( f ) = 2 

( R e + j 



2 

π





fL e ) Z 0 + 2 

( R e + j2π





fL e ) ,

in which R_e represents the resistance of the resistor, L_e represents the inductance of the inductor, and the Z₀ represents the resistance of a load electrically connected to the equalizer.

3. The method as claimed in claim 1, wherein the ideal gain is the product of the frequency-domain function and the transmission line scattering-parameter at a pre-determined frequency.

4. The method as claimed in claim 3, wherein the pre-determined frequency is ½

π

τ

HZ, π

is a constant, and τ

is a delay time.

5. The method as claimed in claim 1, further comprising processing a circuit simulation of the compensated digital signal to confirm if the frequency response of the compensated digital signal is as required.

6. The method as claimed in claim 1, further comprising fine tuning the component impedances derived by the integration and the differentiation in order to make the compensated digital signal close to the ideal gain.

7. The method as claimed in claim 1, wherein the integration is

${\int }_{}^{}$

0 ∞





( H TX - Line 

( f ) ×

H emp 

( f ) ×

H equalizer 

( f ) ) - H ideal 

( f ) 







f = min , 

H TX - Line 

( f )

represents the transmission line scattering-parameter, H_emp(f) represents the frequency-domain function of the digital signal, H_equalizer(f) represents the equalizer scattering-parameter, H_ideal(f) represents the ideal gain, and the min represents the minimum positive number.

8. The method as claimed in claim 1, wherein the differentiation is

$\frac{}{}$

{ 20 

log 10 

⌊

H TX - Line 

( f ) ×

H emp 

( f ) ×

H equalizer 

( f ) ⌋

} 

f ≤

0 , H TX - Line 

( f )

represents the transmission line scattering-parameter, H_emp(f) represents the frequency-domain function of the digital signal, H_equalizer(f) represents the equalizer scattering-parameter.

9. The method as claimed in claim 1, wherein the frequency-domain function of the digital signal is F_Emp(ω

)=(1−

α

)F(ω

)−

α

F(ω

)e<sup>jω

τ</sup>

, F(ω

) represents an original frequency-domain function of the digital signal, and α

represents the de-emphasis parameter.

10. The method as claimed in claim 1, wherein the frequency-domain function of the digital signal is F_Emp(ω

)=(1+α

)F(ω

)−

α

F(ω

)e<sup>jω

τ</sup>

, F(ω

) represents an original frequency-domain function of the digital signal, and α

represents the pre-emphasis parameter.

11. The method as claimed in claim 1, wherein the digital signal is provided by a Peripheral Component Interconnect (PCI) interface, a PCI express (PCIe) interface, a Serial ATA (SATA) interface, or a Parallel ATA (PATA) interface.

12. The method as claimed in claim 1, wherein the digital signal is a single ended signal.

13. The method as claimed in claim 1, wherein the digital signal is a differential signal including a positive input signal and a negative input signal.