Multistage Quadrature Sigma-Delta Modulators for Reconfigurable Multi-Band Analog-Digital Interface in Cognitive Radio Devices
Nowadays, a growing number of parallel wireless communication standards, together with ever-increasing traffic amounts, create a widely acknowledged need for novel radio solutions, such as emerging Cognitive Radio (CR) paradigm. On the other hand, transceiver implementations, especially in mobile terminals, should be small-sized, power efficient, highly integrable, and cheap. Thus, it would be valuable to avoid implementing parallel transceiver units for separate communication modes. However, operating band of this kind of Software Defined Radio (SDR) should be extremely wide (even GHz range), and dynamic range of the receiver should be high (several tens of dBs).