Abstract
A variety of three-dimensional (3-D) transmission line structures were fabricated using low-dielectric-constant benzocyclobutene (BCB) interlayers to achieve low characteristic impedances (Z 0) at millimeter wave frequencies. The effects of structural variations on the Z 0 of the transmission line structures were examined at a frequency of 50 GHz. Two different 3-D coplanar waveguide (CPW) structures, the bottom-ground and the double-ground structures, showed very low Z 0 values of ∼7.3 and ∼9.4 Ω, respectively, at a signal linewidth of 100 μm and a bottom-ground spacing of 20 μm. When the ratio of the spacing of bottom-ground width to the signal linewidth became greater than 2.5, the Z 0 was nearly saturated, showing a minimum Z 0. The thin-film microstrip lines fabricated using the BCB inter layers showed a higher minimum Z 0 of ∼25.5 Ω at a ground plane width of 55 μm and a signal linewidth of 35 μm than the 3-D CPW structures did. Among the 3-D transmission structures, the bottom-ground CPW was shown to be the most efficient structure to achieve a low Z 0 by maximizing the capacitance between the signal and the ground lines at 50 GHz.
Original language | English |
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Pages (from-to) | 1076-1080 |
Number of pages | 5 |
Journal | Journal of the Korean Physical Society |
Volume | 43 |
Issue number | 6 |
State | Published - Dec 2003 |
Keywords
- 3-D CPW Structure
- Benzo-Cyclo-Butene
- Low characteristic impedance transmission line