Wide-tuning, low-voltage 1GHz bandpass filter based on f/sub T/-integration

An integrated bandpass filter based on the f/sub T/-integration technique is experimentally demonstrated for the first time in GHz frequency range. The f/sub T/-integrator configuration employed offers enhanced performance compared to the originally introduced structure with lower supply voltage, more accurate frequency control and less chip area while still maintaining a wide frequency tuning capability. Fabricated in 0.8 /spl mu/m-BiCMOS, the experimental filter obtains a centre frequency tuning over 200% (from 420MHz to 1320MHz) with -52dB THD for output current at 50% modulation index, 30dB spurious free dynamic range and 1dB-compression-point dynamic range of 37dB at Q = 14. The circuit operates at 1.8V-supply voltage with current consumption in each integrator varying from 1.9mA to 4.2mA for the entire tuning range.