Ultra-compact RF passive components employing periodically arrayed ground structure on silicon RFIC

In this work, using a coplanar waveguide employing periodically arrayed ground structure (PAGS) on silicon RFIC, a highly miniaturized and broadband on-chip impedance transformer and 90° hybrid coupler were developed for application to wireless communication system. The size of the impedance transformer was 0.01 mm² on silicon substrate, which was 6.99% of the one fabricated by conventional coplanar waveguide. The transformer showed a good RF performance from 1 to 40 GHz. The 90° hybrid coupler exhibited good performances from 41.75 to 50 GHz, and its size was 0.46×0.55 mm², which is 37% of conventional one.