An Improved Quadrature Voltage-Controlled Oscillator with Through-Silicon-Via Inductor in Three-dimensional Integrated Circuits

Low-power quadrature voltage-controlled oscillator (QVCO) design utilizing transformer-feedback and current-reuse techniques with increased frequency range is proposed in this paper. With increasing demand for QVCOs in on-chip applications, the conventional spiral inductor based approaches for QVCOs has become a major bottleneck due to their large size. To address this concern, we propose to replace the conventional spiral inductor based approaches with through-silicon-via (TSV) inductor based approach in three-dimensional integrated circuits (3D ICs). In addition, the proposed QVCO circuit can provide higher frequency range of operation compared with conventional designs. Experimental results show by replacing conventional spiral transformers with TSV transformers, up to 3.9x reduction in metal resource consumption. The proposed QVCOs achieves a phase noise of -114 $dBc/Hz$@1 $MHz$ and -111.2 $dBc/Hz$@1 $MHz$ at the carrier of 2.5 $GHz$ for toroidal TSV transformed based-QVCO and vertical spiral transformer based-QVCO respectively. The power consumption is only 1.5 $mW$ and 1.7 $mW$ for toroidal TSV transformed based-QVCO and vertical spiral transformer based-QVCO respectively, under the supply voltage of 0.7 $V$.