An Analysis of Multi-Layer Inductors for Miniaturizing of GaAs MMIC

Newly developed multi-layer inductors on GaAs threedimensional MMICs are presented. We analyzed single-, double-, triple-, and quadruple-layer stacked-type inductors in what may be the first report on inductors on a GaAs MMIC with three or more layers. The performance of singleand multi-layer inductors was measured and calculated by electromagnetic field simulation. The multi-layer inductors produce 2–11 times higher inductance than that of conventional inductors on 2DMMICs although they are the same size. This means that the proposed multi-layer inductors have smaller areas with the same inductances than those of conventional inductors. We also conducted the first-ever investigation of how performance factors such as parasitic capacitance, Q-factor, and self-resonant frequency are degraded in multi-layer inductors vis-à-vis those of conventional inductors. A microwave amplifier using multi-layer inductors was demonstrated and found to reduce circuit size by 20%. key words: multi-layer inductor, stacked inductor, three-dimensional MMIC, GaAs