Telecommunications is fundamental to modern society, with nearly everyone on the planet having access to a mobile phone, Wi-Fi, or satellite and terrestrial broadcast systems. This book is a concise analysis of both the basics of telecommunications as well as numerous advanced systems. It begins with a discussion of why we perform modulation of a carrier signal, continuing with a study of noise affecting all telecommunications links, be they digital or analogue in form. Digital communications techniques are examined in . Such an examination is crucial since radio, television, and satellite broadcasts are transmitted using a digital format. Analogue modulations are also considered. The logic behind such an investigation is because, whereas most broadcast systems are moving towards digital transmission, analogue techniques are still very much prevalent (most notably with AM and FM broadcasts). A topic that is often neglected in text books on telecommunications but is at the forefront of concerns transmission lines. This is an important area of work since every length of coaxial cable used to convey signals from an antenna to a receiver is a transmission line. It is vitally important that a transmission line linking a transmitter to the antenna is matched and this topic is explored in great detail in several chapters dealing with Smith charts.