Passive Switched Capacitor RF Front Ends for Spectrum Sensing in Cognitive Radios

This paper explores passive switched capacitor based RF receiver front ends for spectrum sensing. Wideband spectrum sensors remain the most challenging block in the software defined radio hardware design. The use of passive switched capacitors provides a very low power signal conditioning front end that enables parallel digitization and software control and cognitive capabilities in the digital domain. In this paper, existing architectures are reviewed followed by a discussion of high speed passive switched capacitor designs. A passive analog FFT front end design is presented as an example analog conditioning circuit. Design methodology, modeling, and optimization techniques are outlined. Measurements are presented demonstrating a 5 GHz broadband front end that consumes only 4 mW power

Cognitive radio receiver front-ends: RF/analog circuit techniques

This book focuses on the architecture and circuit design for cognitive radio receiver front-ends.  The authors first provide a holistic explanation of RF circuits for cognitive radio systems. This is followed by an in-depth exploration of existing techniques that can be utilized by circuit designers. Coverage also includes novel circuit techniques and architectures that can be invaluable for designers for cognitive radio systems.   • Discusses in detail the circuit-level challenges that exist for cognitive radio systems; • Provides readers with a holistic understanding of RF circuits for cognitive radio systems; • Enables communications engineers and systems designers to design better cognitive radio architectures and communication protocols