Microstrip interconnects with a V conductor are designed, fabricated, and measured to provide a compact solution for designs requiring low characteristic impedance lines. S-parameter curves are shown up to 35 GHz for 0.5-cm-long lines. The 308-μm-deep V structure produces a 33.8-ω line with strong standing waves and reflections under 5 dB. To further reduce the impedance, a partial shield is added that results in 6.7 times reduction of signal line width, near elimination of open-end effect, and excellent correlation with a standard 15-ω microstrip up to 25 GHz. A filter demonstration shows near ideal behavior in the 3 dB response and low return loss when compared to a similar conventional design.
Bibliographical noteFunding Information:
Manuscript received August 30, 2005; revised September 11, 2006. This work was supported by the National Science Foundation under Grant ECS-9996017. Any findings, conclusions, or recommendations expressed in this publication are those of the author and do not necessarily reflect the views of the National Science Foundation S. R. Banerjee with the 3M Corporation in St. Paul, MN 55144 USA (e-mail: email@example.com).
- Microstrip discontinuities
- Stepped impedance filters