Adaptive Multi-Standard RF Front-Ends (Analog Circuits and Signal Processing)

N this information era people are living in a society in which processing, ?ow and Iexchange of information are vital for their existence. Two major issues in such so- ety, which are related to ?ow and exchange of information, are connectivity and mobility. On one hand, computers and Internet provide connectivity and allow communication as well as fast access to large amounts of information. On the other hand, wireless techno- gies bring mobility. People can move and still be able to communicate and have access to various kind of information. Therefore, the functioning of an information society is unthinkable without the use of computers, Internet and wireless technologies. The exp- tations are that in the future they will merge into a unique system for communication, access to information as well as their exchange and processing. The era of wireless communications started in 1901, when Guglielmo Marconi s- cessfully transmitted radio signals across the Atlantic Ocean. From that moment up to now wireless communications experienced explosive growth and became the fastest growing ?eld in the engineering world. Pushed by customer requirements, new wireless techno- gies have been emerging very fast. Each new generation of wireless technologies have brought new features and more complexity. Pushed by market forces to reduce costs, the semiconductor industry has provided new technologies for solid-state circuits implem- tation. Fortunately at the same time with the cost reduction, performance of new te- nologies has been improving.

The design and use of multi-standard RF transceivers is the way to increase hardware flexibility and functionality, as well as to improve the flexibility of set-makers on the market. In the design of multi-standard RF transceivers the efforts will be directed towards improvement of hardware reusability, reconfigurability, programmability and flexibility. This will result in the launching of a software-defined radio.

Since the radio environment is variable, the application of adaptivity in RF transceivers results in the reduction of their power consumption. Eventually, it is reasonable to believe that RF front-ends will be smart in the sense that they will be able to monitor the radio environment and to adapt themselves to the changes in this environment paving the way for a cognitive radio.

Adaptive Multi-Standard RF Front-Ends investigates solutions, benefits, limitations and costs related to multi-standard operation of RF front-ends and their adaptivity to variable radio environments. Next, it highlights the optimization of RF front-ends that allow achieving of maximal performance with a certain power budget while targeting full integration. Also, it investigates possibilities for low-voltage low-power circuit topologies in CMOS technology.

The concepts and considerations presented in this book have been validated through the design and implementation of the reconfigurable multi-band DECT/Bluetooth RF front-end in 0.18 um CMOS technology.

The successful design and implementation of the reconfigurable DECT/Bluetooth RF front-end is the result of systematic approach through all the steps in the design flow of a multi-standard front-end starting with the system level design, continuing with the circuit level design and implementation, and ending with the validation based on measurements.