Improvement the Q-factor of multi-band inductor with 90 μm silicon substrate on plastic

This paper presents the multi-band inductor with 0.18 μm CMOS technology on plastic achieves high Q-factor and small size for multiband applications. The multi-band inductor on VLSI-standard Si Substrate is operated at ultra-wide band range. The operation frequencies are near 3 GHz, 4 GHz, 7.5 GHz and 9 GHz of the Q-factor are 6.5, 6.7, 8 and 11.5 with the inductance 2.1, 1.6, 1.1, 0.6 nH, respectively. After thinning-down the Si substrate to 90 μm and mounting on plastic, the Q-factor can improve 25~31% without changing the inductance due to reducing the parasitic effect from Si-substrate.