This paper covers selected topics related to active components are included. An integrated voltage controlled oscillator; low loss microelectromechanical systems (MEMS) switches and switch networks integrated with GaAs monolithic microwave integrated circuits (MMIC), low-noise amplifiers (LNA) are then presented. The next paper presents a two stage class-AB CMOS power amplifier with improved stability for enhanced data rates for GSM evolution (GSM-EDGE) applications, which additionally includes a study on the efficiency improvement obtained by implementing an envelope tracking architecture. Finally, the section concludes with a paper on the application of digital signal processing techniques in transmitter architectures such as polar, envelope tracking and linear amplification with nonlinear components (LINC), aiming to guarantee increased efficiency.