Electrical interconnections:
ZXnoise method for pseudo-differential transmission

     We have recently introduced a ZXnoise technique relating to a new type of pseudo-differential link. It is intended to provide an improved bandwidth and a good protection against external crosstalk, using only m transmission conductors and one return conductor for m transmission channels. The five papers below provide the background of the ZXnoise method.

[B71] F. Broydé, E. Clavelier, "A new pseudo-differential transmission scheme for on-chip and on-board interconnections", Proc. of the CEM 08 Int. Symp. on Electromagnetic Compatibility, Paris, May 2008, session C7.

[B73] F. Broydé, E. Clavelier, "Pseudo-differential links using a wide return conductor and a floating termination circuit", Proceedings of the 2008 IEEE International Midwest Symposium on Circuits and Systems (MWSCAS), August 10-13, 2008, Knoxville, USA, pp. 586-589.

[B78] F. Broydé, E. Clavelier, "Modeling the interconnection of a pseudo-differential link using a wide return conductor", Proceedings of the 13^th IEEE Workshop on Signal Propagation on Interconnects, SPI 2009, May 12-15, 2009, Strasbourg.

[B81] F. Broydé, B. Démoulin, "Designing a ZXnoise Pseudo-Differential Link", Proc. of the IEEE 18th Topical Meeting on Electrical Performance of Electronic Packaging and Systems, EPEPS 2009, October 19-21, 2009, Tigard, USA, pp. 5-8.

[B82] F. Broydé, E. Clavelier, "Multichannel Pseudo-Differential Links", Proc. of the 2010 IEEE International Symposium on Electromagnetic Compatibility, EMC 2010, Fort Lauderdale, July 2010, Vol. 2, pp. 305-310.

[B89] F. Broydé, E. Clavelier, "Twelve Pseudo-Differential Transmission Schemes", Proc. IEEE 20th Conference on Electrical Performance of Electronic Packaging and Systems, EPEPS 2011, San Jose, USA, pp. 299-302, Oct. 23-26, 2011.

     The two papers below focus on a particular type of transmitting circuit which can be used in the ZXnoise method.

[B74] F. Broydé, G. Broydé, "Two pseudo-differential transmitting circuits producing a constant common-mode current", Proceedings of the 2008 IEEE International Midwest Symposium on Circuits and Systems (MWSCAS), August 10-13, 2008, Knoxville, USA, pp. 269-272.

[B75] F. Broydé, E. Clavelier, "A pseudo-differential transmitting circuit causing reduced common-mode current variations", Proceedings of the 15^th IEEE International Conference on Electronics, Circuits and Systems, ICECS 2008, August 31 - September 3, 2008, Malta, pp. 17-20.

     The papers B71 and B75 use, as an example of ZXnoise link, an interconnection based on the same coplanar-strips-over-return-conductor structure, while the papers B73 and B74 use an interconnection implementing a coplanar-strips-inside-return-conductor structure. The papers B71 and B74 use, as an example of device-level implementation, the same transmitting circuit, whereas the paper B75 uses a different transmitting circuit. Consequently, these papers describe a variety of designs. However, many other types of interconnection and transmitting circuit may be used.

     Our group also introduced a technique for reducing internal crosstalk and echo, referred to as ZXtalk method. The ZXnoise and ZXtalk method may be combined to provide a reduction of echo, internal crosstalk and external crosstalk. The following paper addresses the combination of the ZXnoise method with the special ZXtalk method for completely degenerate interconnections:

[B77] F. Broydé, E. Clavelier, "Echo-free and crosstalk-free transmission in particular interconnections", IEEE Microwave and Wireless Components Letters, Vol. 19, No. 4, April 2009, pp. 209-211.

     The initial set of four patent applications covering the ZXnoise technique is represented by the following PCT applications:

[P35] International application PCT/IB2008/051826 of 8 May 2008 (WO 2008/155676), Pseudo-differential interfacing device having a termination circuit. Inventors: Frédéric Broydé & Evelyne Clavelier. Priority: French patent application 07/04421 of 21 June 2007.

[P36] International application PCT/IB2008/051942 of 16 May 2008 (WO 2009/007864), Pseudo-differential interfacing device having a balancing circuit. Inventors: Frédéric Broydé & Evelyne Clavelier. Priority: French patent application 07/04889 of 06 July 2007.

[P37] International application PCT/IB2008/051982 of 20 May 2008 (WO 2009/007866), Pseudo-differential interfacing device having a switching circuit. Inventors: Frédéric Broydé & Evelyne Clavelier. Priority: French patent application 07/04949 of 09 July 2007.

[P38] International application PCT/IB2008/052102 of 29 May 2008 (WO 2009/013644), Method and device for pseudo-differential transmission. Inventors: Frédéric Broydé & Evelyne Clavelier. Priority: French patent application 07/05260 of 20 July 2007.

     The following patent applications may be used to improve the ZXnoise method, one of the ideas being the combination of suitably adapted concepts of the ZXnoise and ZXtalk methods.

[P39] International application PCT/IB2009/051053 of 13 March 2009 (WO 2010/004442), Pseudo-differential receiving circuit. Inventors: Frédéric Broydé & Evelyne Clavelier. Priority: French patent application 08/03830 of 7 July 2008.

[P40] International application PCT/IB2009/051182 of 20 March 2009 (WO 2010/004444), Multichannel interfacing device having a termination circuit. Inventors: Frédéric Broydé & Evelyne Clavelier. Priority: French patent application 08/03876 of 8 July 2008.

[P41] International application PCT/IB2009/051358 of 31 March 2009 (WO 2010/004445), Multiple-input and multiple-output amplifier having pseudo-differential inputs. Inventors: Frédéric Broydé & Evelyne Clavelier. Priority: French patent application 08/03982 of 11 July 2008.

[P42] International application PCT/IB2009/051557 of 14 April 2009 (WO 2010/004448), Multichannel interfacing device having a balancing circuit. Inventors: Frédéric Broydé & Evelyne Clavelier. Priority: French patent application 08/03985 of 11 July 2008.

[P43] International application PCT/IB2009/052638 of 19 June 2009 (WO 2010/015947), Method for pseudo-differential transmission using modal electrical variables. Inventors: Frédéric Broydé & Evelyne Clavelier. Priority: French patent application 08/04429 of 4 August 2008.

[P44] International application PCT/IB2009/052645 of 19 June 2009 (WO 2010/015948), Method for pseudo-differential transmission using natural electrical variables. Inventors: Frédéric Broydé & Evelyne Clavelier. Priority: French patent application 08/04430 of 4 August 2008.

[P45] International application PCT/IB2009/055287 of 23 November 2009 (WO 2010/079390), Multichannel interfacing device having a switching circuit. Inventors: Frédéric Broydé & Evelyne Clavelier. Priority: French patent application 09/00042 of 8 January 2009.

     The following patent applications extend the applicability of the ZXnoise method to an interconnection which does not use a wide return conductor or which cannot be modeled as a uniform multiconductor transmission line.

[P46] International application PCT/IB2009/055295 of 23 November 2009 (WO 2010/082093), Transmission device using a plurality of elementary return conductors. Inventors: Frédéric Broydé & Evelyne Clavelier. Priority: French patent application 09/00161 of 15 January 2009.

[P48] International application PCT/IB2010/051863 of 28 April 2010, Method for pseudo-differential transmission using a non-uniform interconnection. Inventors: Frédéric Broydé & Evelyne Clavelier. Priority: French patent application 09/04611 of 28 September 2009.