Electrically tuned pre-selection of ultra wide band RF front-end

The module of ultra wide band RF front-end pre-selection is designed in this paper under the idea of software radio, which effectively solves the problems brought by mirror frequency in the superheterodyne receiver. The electrically tuned filters are finally chosen to realize the pre-selection. The ultra wide band RF signal from 30~400MHz is divided into three channels. We control three electrically tuned filters by varying the tuning voltages to achieve the signal filtering of specific center frequency, respectively. The designed novel pre-selection module has satisfying performance as its tuning accuracy is better than that of 2% the tuning center frequency.