Miniaturised integrated passive device balun design with balanced amplitude and phase for Wi‐Fi applications

Abstract

AbstractA miniaturised integrated passive device (IPD) balun design with low insertion loss and balanced amplitude and phase is proposed for Wi‐Fi/Bluetooth applications. In this design, a novel topology based on the modified T‐type filter structure is introduced to offset the parasitic and coupling effects that cause poor balance in IPD design. The proposed balun design is fabricated on a GaAs substrate. The measured insertion loss is lower than 0.9 dB and the measured return loss is >16 dB in the frequency range of 2.2–2.9 GHz. The measured results of amplitude and phase show rather minor imbalances, which are lower than ±0.67 dB and ±1.8° respectively. The fabricated device size is 0.9 mm × 0.6 mm only.