Generation of differential signals

Patent metadata

Field	Value
Publication number	US-9319043-B2
Application number	US-201013576147-A
Country	US
Kind code	B2
Filing date	Feb 2, 2010
Priority date	Feb 2, 2010
Publication date	Apr 19, 2016
Grant date	Apr 19, 2016

Abstract

The invention relates to an apparatus comprising a differential driver module configured to generate at least one differential signal having steep rise and fall times for at least partially reducing common-mode noise. The invention also relates to a method for causing the differential driver to generate the signal and a system comprising the differential driver and a conductor module for transmission of the generated differential signal. A computer program for performing the method and a computer-readable medium is also part of the invention.

First claim

The invention claimed is:

1. An apparatus comprising:
a switch driver to cause, based on an input signal, switching of a plurality of switches; and
a differential driver comprising the plurality of switches coupled to at least two transmission lines to create a differential interface for sending digital data, wherein when the plurality of switches are switched, the differential driver generates at least one differential signal having rise and fall times, wherein the rise and fall times are determined by at least a switching time of the plurality of switches, wherein decreasing the rise and fall times to a range of times causes a reduction of a noise that is common to the at least two transmission lines, wherein each of the at least two transmission lines comprises a signal conductor, wherein the at least two transmission lines share a ground-plane, wherein the shared ground-plane is formed in a predetermined pattern to cause a reduction in amplitudes of frequency components of the noise above a predetermined frequency, and wherein the rise and fall times reduce amplitudes of frequency components of the noise below the predetermined frequency.

2. The apparatus according to claim 1 , wherein the range of times includes one or more of:
10 picoseconds to 30 picoseconds;
10 picoseconds to 20 picoseconds;
5 picoseconds to 20 picoseconds; or
less than 15 picoseconds.

3. The apparatus according to claim 1 , wherein the at least one differential signal comprises at least one of a serial digital data transmission or a parallel digital data transmission.

4. The apparatus according to claim 1 , wherein the apparatus comprises a mobile terminal.

5. The apparatus according to claim 1 , wherein the predetermined frequency has a value of about 3 Gigahertz.

6. The apparatus according to claim 1 , wherein the plurality of switches comprise:
a first high-side switch connected to a first high-side impedance element and a first low-side switch connected to a first low-side impedance element, wherein the first high-side impedance element and the first low-side impedance element are further connected to a first differential output; and
a second high-side switch connected to a second high-side impedance element and a second low-side switch connected to a second low-side impedance element, wherein the second high-side impedance element and the second low-side impedance element are further connected to a second differential output,
wherein a first control input to the first high-side switch and a second control input to the second low-side switch are connected to a first input, and wherein a third control input to the second high-side switch and a fourth control input to the first low-side switch are connected to a second input.

7. The apparatus according to claim 6 , wherein at least one of the first high-side switch, the second high-side switch, the first low-side switch, or the second low-side switch comprises at least one of a resonance tunnel diode or a transistor.

8. The apparatus according to claim 1 , wherein the ground-plane comprises a defected ground-plane filter including carbon nanotube material.

9. The apparatus according to claim 8 , wherein the defected ground filter has a product of relative permeability and permittivity of at least 5000 at the predetermined frequency.

10. The apparatus according to claim 1 , wherein the defected ground-plane filter is implemented in a connector incorporated into the apparatus.

11. The apparatus according to claim 1 , wherein the rise and fall times are less than or equal to 35 picoseconds.

12. The apparatus according to claim 1 , wherein each of the plurality of switches includes an impedance element to cause impedance matching between the differential driver and the at least two transmission lines.

13. A method comprising:
generating, by a switch driver, one or more control signals to cause, based on an input signal, switching of a plurality of switches; and
generating, by a differential driver comprising the plurality of switches coupled to at least two transmission lines to create a differential interface for sending digital data, when the plurality of switches are switched, at least one differential signal having rise and fall times, wherein the rise and fall times are determined by at least a switching time of the plurality of switches, wherein decreasing the rise and fall times to a range of times causes a reduction of a noise that is common to the at least two transmission lines, wherein each of the at least two transmission lines comprises a signal conductor, wherein the at least two transmission lines share a ground-plane, wherein the shared ground-plane is formed in a predetermined pattern to cause a reduction in amplitudes of frequency components of the noise above a predetermined frequency, and wherein the rise and fall times reduce amplitudes of frequency components of the noise below the predetermined frequency.

14. The method according to claim 13 , wherein the range of times includes one or more of:
10 picoseconds to 30 picoseconds;
10 picoseconds to 20 picoseconds;
5 picoseconds to 20 picoseconds; or
less than 15 picoseconds.

15. The method according to claim 13 , wherein the at least one differential signal comprises at least one of a serial digital data transmission or a parallel digital data transmission.

16. The method according to claim 13 , wherein the method is implemented in a mobile terminal.

17. The method according to claim 13 , wherein the predetermined frequency has a value of about 3 Gigahertz.

18. The method according to claim 13 , wherein the plurality of switches comprise:
a first high-side switch connected to a first high-side impedance element and a first low-side switch connected to a first low-side impedance element, wherein the first high-side impedance element and the first low-side impedance element are further connected to a first differential output; and
a second high-side switch connected to a second high-side impedance element and a second low-side switch connected to a second low-side impedance element, wherein the second high-side impedance element and the second low-side impedance element are further connected to a second differential output,
wherein a first control input to the first high-side switch and a second control input to the second low-side switch are connected to a first input, and wherein a third control input to the second high-side switch and a fourth control input to the first low-side switch are connected to a second input.

19. The method according to claim 18 , wherein at least one of the first high-side switch, the second high-side switch, the first low-side switch, or the second low-side switch comprises at least one of a resonance tunnel diode or a transistor.

20. The method according to claim 13 , wherein the ground-plane comprises a defected ground-plane filter including carbon nanotube material.

21. The method according to claim 20 , wherein the defected ground filter has a product of relative permeability and permittivity at least 5000 at the predetermined frequency.

22. The method according to claim 20 , wherein the defected ground filter is implemented in a connector incorporated into an apparatus.

23. The method according to claim 13 , wherein the rise and fall times are less than or equal to 35 picoseconds.

24. The method according to claim 13 , wherein each of the plurality of switches includes an impedance element to c

Assignees

• Voutilainen Martti Kalevi
• Pasanen Pirjo Marjaana
• Oksanen Markku Anttoni
• Seppälä Eira Tuulia
• Ermolov Vladimir Alexsandrovich
• Nokia Technologies Oy

Inventors

• Voutilainen Martti Kalevi
• Pasanen Pirjo Marjaana
• Oksanen Markku Anttoni
• Seppälä Eira Tuulia
• Ermolov Vladimir Alexsandrovich

Classifications

• H04L25/0272 Primary

  Arrangements for coupling to multiple lines, e.g. for differential transmission · CPC title

• H01P1/203

  Strip line filters · CPC title

• H04L25/0276

  Arrangements for coupling common mode signals · CPC title

• H03K17/16 Primary

  Modifications for eliminating interference voltages or currents · CPC title