GaAs MMIC-based RF on-chip spiral inductors with metal shores and patterned ground shields

The design and fabrication of RF on-chip spiral inductors with metal shores (MS) located and patterned ground shields (PGS) inserted between spiral inductors and the GaAs substrate are proposed in this paper, in order to minimize substrate losses. And inductors are processed by the back etching micromachining technology for further improving the performance of inductors. These inductors provide the complete compatibility capability with standard GaAs MMIC process. The measured Q of 4nH on-chip MMIC inductors with MS and PGS are 13 at 5.8 GHz and 14.2 at 6.6 GHz, respectively. Measurement results show that the effect of MS and PGS on the quality factor (Q) of inductors has resulted in the improvement of about 6% and 15% respectively, and on the inductance is almost invariant. Experiments demonstrate that the distributed effect occurrence of the inductor with PGS is postponed, so the model of the RF on-chip MMIC inductor does not take into consideration the distributed effect before 10GHz.