Flexible RF front-end for communication in TV white spaces

A digitally tunable RF front-end for TV white space communication is presented. The front-end covers an RF frequency range of 470 MHz to 860 MHz with a signal bandwidth of 40 MHz. It is based on a heterodyne architecture with a single frequency conversion using an IF of 280 MHz. Among the frequency tunability, the transmitter provides a maximum output power of 17 dBm and the receiver an input sensitivity of -90 dBm as well as a total noise figure of 3.5 dB at maximum gain. The performance of the RF front-end is evaluated by measurements using harmonic and modulated signals.