Sub-GHz wireless systems have become a popular choice for Internet-of-Things (IoT) applications due to their lower cost, lower power consumption and longer transmission range compared to their 2.4 GHz counterpart. This thesis presents a class-AB sub-GHz RF receiver front-end for low power IoT applications. By exploiting transistors' class-AB operation in both the RF and baseband sections, the receiver front-end achieves a very low sensitivity and an elevated blocker tolerance while keeping a low power consumption. Such performance makes the receiver fully compliant with the short-range (e.g. IEEE 802.15.4) application and also suitable for the emerging long-range (e.g. LoRa) application. The proposed RF receiver front-end has been implemented in 0.13um CMOS technology, operates in the 868/915MHz ISM bands, and exhibits an in-band gain of 50dB, noise figure of 2.7dB, out-of-band IIP3 of +2dBm, out-of-band IIP2 of +37dBm, out-of-band P1dB of -10.5dBm, while draining 2.1mA from a 1.2V supply.M.A.S
