The intention of this book is to give the reader an introduction into the area of modern radar techniques based on active array antennas, either for use in development and research or as a decision and planning aid for the authorities within government or industry. In particular, many new possibilities are discussed which should find consideration for future radar systems. I have assumed the general basics of radar technology to be familiar to the reader; introductory literature is widely available. I have tried to present the techniques, procedures and concepts, which can mostly be derived from signal-theoretical views and which are described with approaches and equations, from an engineering point of view, with a minimum of mathematical treatment. As far as is possible, a descriptive and functional explanation is given for each procedure.