Linear Cmos Rf Power Amplifiers for Wireless Applications : Efficiency Enhancement and Frequency-tunable Capability

Advances in electronics have pushed mankind to create devices, ranging from - credible gadgets to medical equipment to spacecraft instruments. More than that, modern society is getting used to―if not dependent on―the comfort, solutions, and astonishing amount of information brought by these devices. One ?eld that has continuously bene?tted from those advances is the radio frequency integrated c- cuit (RFIC) design, which in its turn has promoted countless bene?ts to the mankind as a payback. Wireless communications is one prominent example of what the - vances in electronics have enabled and their consequences to our daily life. How could anyone back in the eighties think of the possibilities opened by the wireless local area networks (WLANs) that can be found today in a host of places, such as public libraries, coffee shops, trains, to name just a few? How can a youngster, who lives this true WLAN experience nowadays, imagine a world without it? This book dealswith the design oflinearCMOS RF PowerAmpli?ers(PAs). The RF PA is a very important part of the RF transceiver, the device that enables wireless communications. Two important aspects that are key to keep the advances in RF PA design at an accelerate pace are treated: ef?ciency enhancement and frequen- tunable capability. For this purpose, the design of two different integrated circuits realizedina0. 11µmtechnologyispresented,eachoneaddressingadifferentaspect. With respect to ef?ciency enhancement, the design of a dynamic supply RF power ampli?er is treated, making up the material of Chaps. 2 to 4.

The RF power amplifier is a key component in a wireless transceiver and is considered by many as the design bottleneck in the transmitting chain. Linear CMOS RF Power Amplifiers for Wireless Applications addresses two fundamental aspects in RF power amplifier design for integration in CMOS technologies at 2.4, 3.7 and 5.2 GHz: efficiency enhancement and frequency agility.

The well-known linearity–efficiency trade-off is circumvented by employing an efficiency-enhancement technique called the dynamic supply RF power amplifier. The design of this system is described with great detail and compared with other efficiency enhancement techniques.

The frequency agility is achieved with a novel impedance matching network based on coupled inductors. The design of a dual-band RF power amplifier is shown, with a careful analysis of the tunable matching network and its interaction with the rest of the circuit.

The considerations and conclusions drawn throughout this book are based on simulation as well as measurement results from the integrated circuit prototypes carefully built and respecting best practices in RF design.