Thesis Examination Committee
Prof Wing Hung KI, ECE/HKUST (Chairperson)
Prof Howard LUONG, ECE/HKUST (Thesis Supervisor)
Prof George YUAN, ECE/HKUST
With the proliferation of portable wireless application and wireless sensor networks, ultra-low-power (ULP) radios have attracted great attention. To maximize the battery lifetime and to enable operation with harvested energy, it is critical to minimize power consumption of these radios and to operate under ultra-low-voltage (ULV) supply.
Low-noise amplifier (LNA), as the first active block in any radio, needs to provide impedance matching and enough gain while maintaining low noise and high linearity. More challengingly, all those requirements always conflict with low power consumption and low voltage. As the CMOS processes are aggressively scaled, ultra-low-voltage design is necessary for device reliability. However, ultra-low voltage supply limits the voltage swing, increases the non-linearity, and ultimately degrades the signal-to-noise performance of LNAs.
In this thesis, to improve the linearity of the LNA, a novel linearization technique is proposed to cancel the second-order and third-order nonlinear terms in the intrinsic transconductance of CMOS devices. In addition, the drain-source impedance nonlinearity is also suppressed by optimizing the loading impedance of LNA. Finally, both current reuse and trans-conductance boosting techniques are also employed and combined to achieve low power consumption.
The proposed LNA is successfully designed and integrated as part of ULV ULP receiver for BLE, IOT, and WSN applications. It achieves input-referred second-order intermodulation point IIP2 of 44.5dBm with 42dB improvement and input-referred third-order intermodulation point IIP3 of 16dBm with 13dB improvement with NF of 3.2dB while consuming only 230uW power with 0.5V supply voltage.