Open AccessHigh‐performance stacked‐coil transformers with thick metal layers
Author(s) -
Kim Cheol Ho,
Park Bonghyuk
Publication year - 2014
Publication title -
electronics letters
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.375
H-Index - 146
eISSN - 1350-911X
pISSN - 0013-5194
DOI - 10.1049/el.2014.2502
Subject(s) - materials science , electromagnetic coil , benzocyclobutene , transformer , coil tap , optoelectronics , electrical engineering , aluminium , printed circuit board , radio frequency , composite material , rogowski coil , engineering , dielectric , voltage
Miniaturised stacked‐coil radio‐frequency (RF) transformers were fabricated with thick metal layers using the low‐cost anodised aluminium substrate process. The transformer consists of a 34 μm‐thick substrate‐buried copper lower coil and a 30 μm‐thick copper/gold upper coil with a 3 μm‐thick benzocyclobutene (BCB) interlayer between the coils. Owing to extremely low losses and tight coupling, the fabricated transformers achieved very low insertion losses as low as 0.28 dB and high maximum available gains of up to 0.96 at GHz frequencies. The results verify that the stacked‐coil transformer with thick metal layers can be a promising component for high‐performance miniaturised RF circuits.