volume | PIER Journals

Abstract

MEMS phase shifter has been developed using inductors. The design consists of a CPW line capacitively and inductively loaded by the periodic set of inductors and electrostatic force actuated MEMS switches as capacitors. By applying a single bias voltage on the line, the characteristic impedance can be changed, which in turn changes the phase velocity of the line and creates a true time delay phase shift. The governing equations for the impedance and loss are derived. The ABCD matrix is defined for a unit cell and multi-cell DMTL phase shifter to extract scattering parameters equations. The MEMS switch is actuated by a 39 voltage waveform using a high resistance bias line. Estimated spring constant and switching time is 22 N/m and 3 μs, respectively. The structure is designed for Ka-band frequency range. The acceptable frequency range for the design containing 21 cells is between 26 GHz and 27 GHz and optimum condition occurs at 26.3 GHz. For the whole structure and optimum condition the un actuated position results in a return loss -16 dB and insertion loss of -1.65 dB. The actuated position results in a return loss -12.5 dB and insertion loss of -1.6 dB. The phase shift for the whole structure is 190 degree. The optimum condition can be easily changed by modifying the design parameters. The spacing in the proposed structures is S = 250 μm. The structure is also low loss. The length and the loss per bit with the phase shift of 270^◦ are decreased by 37.5 percent and 21 percent respectively.

1. Wang, Z., B. Yan, R. M. Xu, and Y. Guo, "Design of a Ku band six bit phase shifter using periodically loaded-line and switched-line with loaded-line," Progress In Electromagnetics Research, Vol. 76, 369-379, 2007.
doi:10.2528/PIER07071904 Google Scholar

2. Akdagli, A., K. Guney, and B. Babayigit, "Clonal selection algorithm for design of reconfigurable antenna array with discrete phase shifters," Journal of Electromagnetic Waves and Applications, Vol. 21, No. 2, 215-227, 2007.
doi:10.1163/156939307779378808 Google Scholar

3. Barker, N. S. and G. M. Rebeiz, "Distributed MEMS true-time delay phase shifters and wide-band switches," IEEE Trans. Microwave Theory and Tech., Vol. 46, No. 1, 1881-1890, 1998.
doi:10.1109/22.734503 Google Scholar

4. Borgioli, A., Y. Liu, A. S. Nagra, and R. A. York, "Low-loss distributed MEMS phase shifter," IEEE Microwave Guided Wave Lett., Vol. 10, 7-9, 2000.
doi:10.1109/75.842070 Google Scholar

5. Hayden, J. S. and G. M. Rebeiz, "2-bit MEMS distributed X-band phase shifters," IEEE Microwave Guided Wave Lett., Vol. 10, 540-542, 2000.
doi:10.1109/75.895096 Google Scholar

6. Liu, Y., A. Borgioli, A. S. Nagra, and R. A. York, "K-band 3-bit low-loss distributed MEMS phase shifter," IEEE Microwave Guided Wave Lett., Vol. 10, 415-417, 2000.
doi:10.1109/75.877230 Google Scholar

7. Hayden, J. S., A. Makczewski, J. Kleber, C. L. Goldsmith, and G. M. Rebeiz, "2 and 4-bit DC-18 GHz microstrip MEMS distributed phase shifters," IEEE MTT-S Int. Microwave Symp. Dig., 219-222, May 2001.

8. Pillans, B., S. Eshelman, A. Malczewski, J. Ehmke, and C. L. Goldsmith, "Ka-band RF MEMS phase shifters," IEEE Microwave Guided Wave Lett., Vol. 9, 520-522, 1999.
doi:10.1109/75.819418 Google Scholar

9. Kim, M., J. B. Hacker, R. E. Mihailovich, and J. F. DeNatale, "A DC-to-40 GHz four-bit RF MEMS true-time delay network," IEEE Microwave Wireless Comp. Lett., Vol. 11, 56-58, 2001.
doi:10.1109/7260.914301 Google Scholar

10. Hayden, J. S. and G. M. Rebeiz, "Very low-loss distributed X-band and Ka-band MEMS phase shifters using metal-airmetal capacitors," IEEE Trans. on Microwave Theory and Tech., Vol. 51, No. 1, 309-314, 2003.
doi:10.1109/TMTT.2002.806520 Google Scholar

11. Hung, J.-J., L. Dussopt, and G. M. Rebeiz, "Distributed 2- and 3-bit W-band MEMS phase shifters on glass substrates," IEEE Trans. on Microwave Theory and Tech., Vol. 52, No. 2, 600-606, 2004.
doi:10.1109/TMTT.2003.821941 Google Scholar

12. Hayden, J. S., High-performance digital X-band and Ka-band distributed MEMS phase shifters, Ph.D. thesis, University of Michigan, Ann Arbor, 2002.

13. Barker, N. S., Distributed MEMS transmission lines, Ph.D. thesis, University of Michigan, Ann Arbor, 1999.

14. Rao, S. S., Mechanical Vibrations, Addison-Wesley Publishing Company, 1995.

15. Wolff, E. A., Microwave Engineering and Systems Applications, John Wiley & Sons Publication, 1988.

16. Pozar, D. M., Microwave Engineering, Addison-Wesley Publishing Company, 1990.

17. Hoffmann, R. K., Handbook of Microwave Integrated Circuits, Artech House, 1987.

18. Rebeiz, G. M., RF MEMS Theory Design and Technology, John Wiley & Sons Publication, 2003.

19. Greenhouse, H. M., "Design of planar rectangular microelectronic inductors," IEEE Transaction on Parts Hybrids and Packaging, Vol. 10, No. 2, 101-109, 1974.
doi:10.1109/TPHP.1974.1134841 Google Scholar

Mr. Saeid Afrang

Professor Burhanuddin Yeop Majlis