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Abstract

Quadrature voltage-controlled oscillators (QVCOs) are widely used in radio-frequency integrated circuit transceiver architectures. Different wireless communication systems call for different specifications, in particular, in terms of power consumption. For example, for the emerging Internet-of-Things (IoT) applications, all system blocks including the QVCO should operate from a low voltage supply and have a low power consumption. This is in part due to the size and energy resource limitations of the IoT nodes. This thesis presents the design and successful validation of an ultra-low-power QVCO which can operate in both 2.4 GHz and 5 GHz bands which are two of the popular unlicensed industrial, scientific, and medical (ISM) bands. A proof-of-concept prototype of the proposed structure has been designed and fabricated in a 65-nm CMOS process. When operating from 2.35 to 2.51 GHz (tuning voltage from 0 to 1 V), it consumes 0.58 mW from a 0.5-V supply, with a phase noise of -110.10 dBc/Hz at 1 MHz offset and a figure of merit (FOM) of -184.01 dBc/Hz. When operating from 4.81 to 5.26 GHz, again from a 0.5-V supply, the power consumption is 0.247 mW, with a phase noise of -105.10 dBc/Hz at 1-MHz offset and a FOM of -188.25 dBc/Hz. The measured performance of the prototype is compared favorably with that of the state-of-the-art designs.