volume | PIER Journals

Abstract

Investigations are conducted into low-loss, low-dispersion fully shielded membrane-supported striplines designed for use in a millimeter-wave multi-chip-module. Two types of transmission line are studied: a membrane-supported shielded stripline and a novel variation of this where the membrane material is removed in areas of little mechanical importance to reduce attenuation and dispersion. The latter is possible through the exploitation of a versatile micromachining technique using SU-8 for both the membrane and the shielding. The micromachining techniques used for the fabrication of the micro-shielding allows for the conformal packaging of lines and devices, with the ultimate aim of the realization of novel components for 3D system-in-a-package type modules. Extensive simulated results obtained from rigorous electromagnetic modeling are presented that fully characterize both types of line and, where possible, are compared to measured results. Loss mechanisms are investigated for both line types and simulations suggest that losses as low as 0.39 dB/cm and effective relative permittivities of less than 1.05 are possible at a frequency of 100 GHz, comparing well with other demonstrated membrane supported transmission lines. The methods used for investigation of line characteristics and analysis of single-mode, non-leaky frequency range are applicable to any variety of membrane supported transmission line. The basics of line fabrication are given along with measurement results and de-embedding techniques used at V-band.

1. Chi, C.-Y. and G. M. Rebeiz, "Planar millimeter-wave microstrip lumped elements using micro-machining techniques," IEEE Int. Microwave Theory Tech. Symposium Dig., 657-660, May 1994.

2. Robertson, S. V., A. R. Brown, L. P. B. Katehi, and G. M. Rebeiz, "A 10-60-GHz micromachined directional coupler," EEE Trans. Microwave Theory Tech., Vol. 46, No. 11, 1845-1849, Nov. 1998.
doi:10.1109/22.734498

3. Raskin, J. P., "Micromachined W-band passive components for communication applications," MSTnews, 02/01, 13-15, Feb. 2001.

4. Trimmer, W. S. N., "Microrobots and micromechanical systems," Sensors and Actuators, Vol. 19, 267-287, 1988.

5. Rebeiz, G. M., L. P. B. Katehi, T. M. Weller, C. Y. Chi, and S. V. Robertson, "Micromachined membrane filters for microwave and millimetre-wave applications (Invited article)," Int. J. of Microwave and Millimeter-wave Computer Aided Engineering, Vol. 7, 149-166, Feb. 1997.
doi:10.1002/(SICI)1522-6301(199703)7:2<149::AID-MMCE1>3.0.CO;2-N

6. Petersen, K. E., "Silicon as a mechanical material," Proc. IEEE, Vol. 70, No. 5, 420-457, May 1982.
doi:10.1109/PROC.1982.12331

7. Moore, D. F. and R. R. A. Syms, "Recent developments in micromachined silicon," Electronics and Communication Engineering Journal, Vol. 11, No. 6, 261-270, Dec. 1999.
doi:10.1049/ecej:19990603

8. Mehregany, M., "Microlectromechanical systems," IEEE Circuits and Devices, Vol. 9, 14-22, Jul. 1993.

9. Rebeiz, G. M., RF MEMS: Theory Design and Technology, John Wiley and Sons, 2003.

10. Herrick, K. J., T. A. Schwarz, and L. P. B. Katehi, "Simicromachined coplanar waveguides for use in high-frequency circuits," IEEE Trans. Microwave Theory Tech., Vol. 46, No. 6, 762-768, Jun. 1998.
doi:10.1109/22.681198

11. Newlin, D. P., A.-V. H. Pham, and J. E. Harriss, "Development of low loss organic micromachined interconnects on silicon at microwave frequencies," IEEE Trans. On Components and Packaging Technologies, Vol. 25, No. 3, 506-510, Sep. 2002.
doi:10.1109/TCAPT.2002.803654

12. Drayton, R. F. and L. P. B. Katehi, "Development of self-packaged high frequency circuits using micromachining techniques," IEEE. Trans. Microwave Theory Tech., Vol. 41, No. 9, 2073-2080, Sep. 1995.
doi:10.1109/22.414543

13. Park, J. Y., C. W. Baek, S. Jung, H. T. Kim, Y. Kwon, and Y. K. Kim, "Novel micromachined coplanar waveguide transmission lines for applications in millimetre-wave circuits," Journal of Applied Physics, Vol. 39, 7120-7124, 2000.

14. Herrick, K. J., T. A. Schwarz, and L. P. B. Katehic, "Simicromachined coplanar waveguides for use in high-frequency circuits," IEEE Trans. Microwave Theory Tech., Vol. 46, No. 6, 762-768, Jun. 1998.
doi:10.1109/22.681198

15. Ponchak, G. E., A. Margomenos, and L. P. B. Katehi, "Low-loss CPW on low-resistivity Si substrates with a micromachined polyimide interface layer for RFIC interconnections," IEEE Trans. Microwave Theory Tech., Vol. 49, No. 5, 866-870, 2001.
doi:10.1109/22.920142

16. Newlin, D. P., A.-V. H. Pham, and J. E. Harris, "Development of low loss organic-micromachined interconnects on silicon at microwave frequencies," IEEE Trans. Components and Packaging Technologies, Vol. 25, No. 3, 506-510, Sep. 2002.
doi:10.1109/TCAPT.2002.803654

17. Weller, T. M., L. P. Katehi, and G. M. Rebeiz, "High performance microshield line components," IEEE Trans. Microwave Theory Tech., Vol. 43, No. 3, 534-543, Mar. 1995.
doi:10.1109/22.372098

18. Lee, K. Y., N. LaBianca, S. A. Rishton, S. Zolgharnain, J. D. Gelorme, J. Shaw, and T. H. P. Chang, "Micromachining applications of a high resolution ultrathick photoresist," J. Vacuum Science and Technology B., Vol. 13, No. 6, 3012-3016, Nov./Dec. 1995.
doi:10.1116/1.588297

19. Lorenz, H., M. Despont, N. Fahrni, N. LaBianca, P. Renaud, and P. Vettiger, "SU-8: A low-cost negative resist for MEMS," J. of Micromechanical Microengineering, Vol. 7, 121-124, 1997.
doi:10.1088/0960-1317/7/3/010

20. Despont, M., H. Lorenz, N. Fahrni, J. Brugger, P. Renaud, and P. Vettiger, "High-aspect-ratio, ultrathick, negative-tone near-UV photoresist for MEMs applications," IEEE Proc. Int. Workshop on Micro-Electro Mechanical Systems, 518-522, Jan. 1997.

21. Lorenz, H., M. Laudon, and P. Renaud, "Mechanical characterization of a new high-aspect-ratio near UV-photoresist," J. Microelectronic Engineering, Vol. 41/42, 371-374, 1998.
doi:10.1016/S0167-9317(98)00086-0

22. Farrington, N. E. S., "Micromachined transmission line interconnects for millimetre-wave multi-chip modulesm,", Ph.D. Thesis, School of Electrical and Electronic Engineering, the University of Leeds, 2005.

23. Shu, Y., X. Qi, and Y. Wang, "Analysis equation for shielded suspended substrate microstrip line and broadside-coupled stripline," IEEE Int. Microwave Theory Tech. Symposium Dig., 693-696, 1987.

24. High Frequency Structure Simulator (HFSS) Version 12, Ansoft, Pittsburgh, PA, USA.

25. Rizzi, P. A., Microwave Engineering --- Passive Circuits, Prentice Hall International Inc., 1988.

26. Shigesawa, H., M. Tsuji, and A. A. Oliner, "Simultaneous propagation of bound and leaky dominant modes on printed circuit lines: A new general effect," IEEE Trans. Microwave Theory Tech., Vol. 43, No. 12, 3007-3019, Dec. 1995.
doi:10.1109/22.475667

27. Tsuji, M., H. Shigesawa, and A. A. Oliner, "New interesting leakage behaviour on coplanar waveguides of finite and infinte widths," IEEE Trans. Microwave Theory Tech., Vol. 39, No. 12, 2130-2137, Dec. 1991.
doi:10.1109/22.106555

28. Oliner, A. A., "Leaky waves: Basic properties and applications," Asia-Pacific Microwave Conference Proc., APMC'97, Vol. 1, 397-400, Dec. 1997.
doi:10.1109/APMC.1997.659407

29. Mesa, F. and R. Marquis, "Low frequency leaky regime in covered multilayered structures," IEEE Trans. Microwave Theory Tech., Vol. 44, No. 9, 1521-1525, Sep. 1996.
doi:10.1109/22.536599

30. Nghiem, D., J. T. Williams, D. R. Jackson, and A. A. Oliner, "Leakage of the dominant mode on stripline with a small air gap," IEEE Trans. Microwave Theory Tech., Vol. 43, No. 11, 2549-2556, Nov. 1995.
doi:10.1109/22.473177

31. Yaozhong, L., C. Kimin, and T. Itoh, "Non-leaky coplanar (NLC) waveguides with conductor backing," IEEE Trans. Microwave Theory Tech., Vol. 43, No. 5, 1067-1072, May 1995.
doi:10.1109/22.382067

32. Mesa, F., A. A. Oliner, D. R. Jackson, and M. J. Freire, "The influence of a top cover on the leakage from microstrip line," IEEE Trans. Microwave Theory Tech., Vol. 48, No. 12, 2240-2248, Dec. 2000.
doi:10.1109/22.898970

33. Nghiem, D., J. T. Williams, D. R. Jackson, and A. A. Oliner, "Suppression of leakage on stripline and microstrip structures," IEEE Int. Microwave Theory Tech. Symposium Dig., Vol. 1, 145-148, May 1994.

34. Collin, R. E., Field Theory of Guided Waves, McGraw-Hill, 1960.

35. Godshalk, E. M., "Generation and observation of surface waves on dielectric slabs and coplanar structures," IEEE Int. Microwave Theory Tech. Symposium Dig., 923-925, 1993.
doi:10.1109/MWSYM.1993.277038

36. Dib, N. I., W. P. Harokopus, Jr., P. B. Katehi, C. C. Ling, and G. M. Rebeiz, "Study of a novel planar transmission line," IEEE Int. Microwave Theory Tech. Symposium Dig., 623-626, 1991.

37. Weller, T. M., G. M. Rebeiz, and L. P. Katehi, "Experimental results on microshield transmission line circuits," IEEE Int. Microwave Theory Tech. Symposium Dig., 827-830, 1993.
doi:10.1109/MWSYM.1993.276747

38. Cheng, H., J. F. Whitaker, T. M. Weller, and L. P. B. Katehi, "Terahertz-bandwidth characterisation of coplanar waveguide via time domain electro-optic sampling," IEEE Int. Microwave Theory Tech. Symposium Dig., 477-480, 1994.

39. Duwe, K., S. Hirsch, R. Judaschke, and J. Muller, "Micromachined coplanar waveguides on thin HMDSN-membranes," 25th Int. Conference on Infrared and Millimeter Waves Digest, 297-298, Sep. 2000.
doi:10.1109/ICIMW.2000.893040

40. Liu, W. Y., D. P. Steenson, and M. B. Steer, "Membrane-supported CPW with mounted active devices," IEEE Microwave and Wireless Components Letters, Vol. 11, No. 4, 167-169, Apr. 2001.
doi:10.1109/7260.916332

41. Advanced Wave Research Corporation, Microwave Office, 1960 E. Grand Avenue, Suite 430, CA 90245.

Dr. Novak E. S. Farrington

Dr. Stavros Iezekiel