Towards a broadband front-end for cooperative spectrum sensing networks

Cooperative spectrum sensing in cognitive radio (CR) avoids hidden terminal problems common to network architectures with central sensing nodes. It also lowers the requirements for the sensing radio front-ends. This paper presents a multi-chip module RF front-end implemented from custom RFICs realized in an 0.25 μm SiGe BiCMOS technology. Using an up/down-conversion heterodyne architecture, the front-end achieves a conversion gain exceeding 17.2 dB and a frequency range up to 4.5 GHz. The noise figure between 15.4 dB and 19.8 dB and the input referred third order intercept point (IIP3) of -7.5dBm constitute a noise/linearity trade-off and are acceptable for compact distributed sensing nodes. The module draws 150mA from a single 5V supply. It was validated in real-world sensing scenarios, combined with a broadband discone antenna, external local oscillators, and a Virtex 6 FPGA evaluation board.