Circuits and Systems for Radiofrequency and Telecommunications

This chapter describes architectures and circuits for telecommunication systems using as reference the structure of a radio receiver, since it includes most of the functional units found in telecommunication equipments. A first section discuss the functional architecture, starting from classic Heterodyne, with discussion on image rejection solutions, and introducing direct conversion (ZIF) and software radio. The following sections describe the various modules, with circuit details: RF amplifiers and Mixers with related problems of nonlinearity in section 2; Phase Lock Loops and signal sources in general: synthesizers and DDS in section 3. The migration of electronic systems towards digital solutions includes telecommunication equipments, which include more and more significant digital parts. That means the processing chain must include A-to-D and D-to-A functions, with characteristic suited for each application. Section 4 describes ADC and DAC units and circuits, with details of the architectures which allow to achieve the performance required in telecommunication, such as residue and pipeline converters, with discussion of parameters and tradeoffs.