In this paper a novel method for crosstalk reduction is proposed. This is achieved through using the step shaped transmission line, which basically attempts to create steps along the transmission lines to decrease the crosstalk, while having negligible variation in return loss. To this end, various simulations are carried out to get an intuition regarding the underlying processes conducted to the far-end crosstalk, thereby enabling to optimize the far-end crosstalk, and simultaneously to yield a small variation in the return loss. Accordingly, a conventional coupled transmission line is employed as a benchmark, enabling to have an idea regarding the impact of the proposed method in terms of the ability to decrease the far-end cross talk. Furthermore, the proposed transmission line and the benchmark structure are fabricated and then evaluated to verify the experimental results to that of the simulation. In addition, comprehensive parametric studies have been carried out to get insight on the effect of various adjustable parameters over the crosstalk. The obtained results show that the crosstalk is decreased more than 4 dB over the entire operating bandwidth. Some advantages such as ease of design and fabrication have made the proposed technique an advisable method when dealing with low crosstalk.
2. Kami, Y. and R. Sato, "Analysis of radiation characteristics of a finite-length transmission line using a circuit-concept approach," IEEE Trans. Electromagnetic Compatibility, Vol. 30, 114-121, May 1988.
3. Kami, Y. and R. Sato, "Crosstalk of finite length transmission lines in arbitrary directions on the same ground," Proc. 1992 IEEE Int. Symp. Electromagn. Compat., 247-250, Aug. 1992.
4. Ponchak, G. E., D. Chun, J. Yook, and L. P. B. Katehi, "Experimental verification of the use of metal filled via hole fences for crosstalk control of microstrip lines in LTCC packages," IEEE Trans. Advanced Packing, Vol. 24, No. 1, Feb. 2001.
5. You, H. and M. Soma, "Measurement and simulation of crosstalk reduction by discrete discontinuities along coupled PCB traces," IEEE Trans. Instrumentation and Measurement, Vol. 43, No. 2, 170-175, Apr. 1994.
6. Marshall, J. B., "Flat cable aids transfer of data," Electron., Vol. 4, 89-94, 1973.
7. Krage, M. K. and G. I. Haddad, "Characteristics of coupled microstrip lines II: Evaluation of coupled-line parameters," IEEE Trans. Microwave Theory Tech., Vol. 18, 222-228, Apr. 1970.
8. Gilb, J. P. and C. A. Balanis, "Pulse distortion on multilayer coupled microstrip lines," IEEE Trans. Microwave Theory Tech., Vol. 37, 1620-1627, Oct. 1987.
9. Paul, C. R., Analysis of Multi Conductor Transmission Lines, Wiley-Inter Sciences, New York, 1994.
10. Li, S., Y. Liu, Z. Song, and H. Hu, "Analysis of crosstalk of coupled transmission lines by inserting additional traces grounded with vias on printed circuit boards," Asia-Pacific Conferenceon Environmental Electromagnetics, 451-454, Nov. 2003.
11. Kim, J., W. Ni, and E. C. Kan, "Crosstalk reduction with nonlinear transmission lines for high-speed VLSI system," IEEE Custom Integrated Circuits Conference, 869-872, Sep. 10-13, 2006.
12. Mbairi, F. D., W. P. Siebert, and H. Hesselbom, "High-frequency transmission lines crosstalk reduction using spacing rules," IEEE Transactions on Components and Packaging Technologies, Vol. 31, No. 3, 601-610, Sep. 2008.
13. Lee, K., H.-B. Lee, H.-K. Jung, J.-Y. Sim, and H.-J. Park, "Serpentine guard trace to reduce far-end crosstalk and even-odd mode velocity mismatch of microstrip lines by more than 40%," Proceedings 57th Electronic Components and Technology Conference, 329-332, May 29-Jun. 1, 2007.