An RF On-Chip Transformer With Fe3O4/GO Nanocomposite Film

In this work, the preparation of Fe
₃
O
₄
/graphene oxide (GO) nanocomposite and its application in radio frequency (RF) on-chip transformer was investigated. The Fe
₃
O
₄
/GO nanocomposite was synthesized by using solvothermal method in the presence of GO and integrated into an on-chip transformer by using a novel post-CMOS process. The experimental results show that the Fe
₃
O
₄
nanoparticles (with ~13 nm in diameter) are uniformly attached onto the surface of GO and the nanocomposite exhibits typical ferromagnetic behavior. Compared with the identical structural air-core transformer, the inductance (L), quality factor (Q), and coupling coefficient (K) of the device with Fe
₃
O
₄
/GO nanocomposite film are increased by 28%, 24%, and 11% at 1 GHz, respectively. The enhancement effect of the magnetic film on the RF performance of the transformer has been maintained until 2 GHz. It is believed that Fe
₃
O
₄
/GO nanocomposite has great potential application in RF on-chip transformers with operation frequency below 2 GHz.