Radio-frequency (RF) circuits and systems are ubiquitous parts of any electronic gadget and instrument that are widely used by the general public. RF design is often considered to be one of the most challenging areas in electrical engineering. This course series promises to deliver a comprehensive overview of RF circuits and systems. The first course covered in this series is primarily on basic concepts in RF design. Concepts such as linearity and noise will be presented and figure-of-merits to evaluate the linearity and noise performance of the RF systems will be introduced. Specifically, the course first goes over the basics of wireless transmitters and receivers. Next, the fundamental concept of power transfer in RF circuits will be briefly studied. This is followed by the analysis of large-signal behavior and the associated impairments such as gain compression and intermodulation. Next, device noise will be studied and ways of modeling the impact of various sources of noise in electronic circuits will be investigated and the concepts of noise figure and noise temperature will be introduced. Finally, the course will look at important performance parameters such as receiver sensitivity and dynamic range and study these parameters in terms of noise performance and distortion.