2000 IEEE. Personal use of this material is permitted. However, permission to reprint/republish this material for advertising or promotional purposes or for creating new collective works for resale or redistribution to servers or lists, or to reuse any copyrighted component of this work in other works must be obtained from the IEEE.

IEEE Transactions on Microwave Theory and Techniques
Volume 48 Number 1, January 2000

Table of Contents for this issue

Complete paper in PDF format

New Miniature Broad-Band CPW-to-Slotline Transitions

Khelifa Hettak, Nihad Dib, Senior Member, IEEE A. Sheta, Amjad A. Omar, Gilles-Y. Delisle, Fellow, IEEE Malcolm Stubbs and Serge Toutain

Page 138.

Abstract:

This paper proposes a novel class of uniplanar coplanar waveguide (CPW)-to-slotline transitions, which is particularly suitable for monolithic millimeter-wave integrated circuits. Instead of using CPW series stub printed in the ground plane, as the case in classical CPW-to-slotline transition, this paper shows the capability to use a CPW series stub printed in the center conductor of the CPW. Compared to classical CPW-to-slotline transitions, the proposed transitions have the following advantages: additional degrees of freedom, lower radiation loss, larger bandwidth, higher compactness, and a major reduction of the number of air bridges that are potentially expensive to build. One alternative configuration that appears to have some merit involves the use of the slotline ring resonator, which does not suffer from open-end or short-end effects and, therefore, gives more accurate resonance frequency, provides an accurate localized zero or infinite impedance point, and maintains low- or high-input impedance values over a wide frequency range, depending on the feed type. A principle of achieving such high-quality transitions is detailed and also confirmed by experimental and theoretical results, which are in good agreement up to 50 GHz. A maximum fractional bandwidth of 160% is achieved for a 10-dB return loss, and the corresponding insertion loss is less than or equal to 2 dB.

References

  1. J. Izadian and S. Izadian, Microwave Transition Design, Norwood, MA : Artech House, 1988.
  2. A. Nesic, "Endfire slotline antennas excited by a coplanar waveguide", in IEEE AP-S Symp. Dig., 1991, pp.  700- 702. 
  3. T. Hirota and H. Ogawa, "Uniplanar MMIC hybrids-A proposed new MMIC structure", IEEE Trans. Microwave Theory Tech., vol. MTT-35 , pp.  576- 581, June  1987 .
  4. H. Ogawa, M. Aikawa and K. Morita, "Integrated balanced BPSK and QPSK modulators for the Ka -band", IEEE Trans. Microwave Theory Tech., vol. MTT-29, pp.  227- 234 , Mar.  1982 .
  5. D. Cahana, "A new coplanar waveguide/slotline double-balance mixer", in IEEE MTT-S Symp. Dig., 1989, pp.  967- 968. 
  6. S. Sugawara, Y. Maita, K. Adachi, K. Mori and K. Mizuro, "A mm-wave tapered slot antenna with improved radiation pattern", in IEEE MTT-S Symp. Dig., 1997, pp.  959- 962. 
  7. T. Ho and S. Hart, "A novel broad-band coplanar waveguide to slotline transition", IEEE Microwave Guided Wave Lett., vol. 2, pp.  415- 416, Oct.  1992 .
  8. C. Ho, L. Fan and K. Chang, "Broad-band uniplanar hybrid-ring and branch-line couplers", IEEE Trans. Microwave Theory Tech., vol. 41, pp.  2116- 2125, Dec.  1993 .
  9. W. Grammer and K. S. Yngvesson, "Coplanar waveguide transitions to slotline: design and microprobe characterization", IEEE Trans. Microwave Theory Tech., vol. 41, pp.  1653- 1658 , Sept.  1993 .
  10. V. Trifunovic and B. Jokanovic, "New uniplanar balun", Electron. Lett., vol. 27, pp.  813- 815, May  1991 .
  11. N. Dib, R. Simons and L. Katehi, "New uniplanar transitions for circuits and antenna applications", IEEE Trans. Microwave Theory Tech., vol. 43 , pp.  2868- 2873, Dec.  1995 .
  12. K. Hettak, J. Coupez, T. Le Gouguec, S. Toutain, P. Legaud and E. Penard, "Improved CPW to slotline transitions ", in IEEE MTT-S Symp. Dig., San Francisco , CA, 1996, pp.  1831- 1834. 
  13. K. Ma and T. Itoh, "Analysis and applications of a new CPW-slotline transition", IEEE Trans. Microwave Theory Tech., vol. 47, pp.  426- 432, Apr.  1999 .
  14. K. Chang, Microwave Ring Circuits and Antennas, ser. (Wiley Microwave Opt. Eng. Series), New York : Wiley , 1996.
  15. N. Dib and L. Katehi, "Modeling of shielded CPW discontinuities using the space domain integral equation method (SDIE)", J. Electromag. Waves Applicat., pp.  503- 523, Apr.  1991.
  16. K. Hettak, N. Dib, A. Sheta and S. Toutain, "A class of novel uniplanar series resonators and their implementation in original applications", IEEE Trans. Microwave Theory Tech., vol. 46, pp.  1270- 1276 , Sept.  1998.