High-frequency high-Q BiCMOS current-mode bandpass filter andmobile communication application

摘要

The design of a tunable high-frequency fully integrablencurrent-mode bandpass filter is presented using a complementarynhigh-performance BiCMOS process. The new architecture of this filter isnbased on impedance simulation and employs current controlled conveyors.nThe Q-factor and the center frequency can be electronically controllednwith dc bias currents over a broad range of values, thus allowing easyntuning of this filter. An application to a mobile communication IFnreceiver channel centered at 85 MHz and with 1-MHz bandwidth based onnthe cascade of two identical second-order bandpass cells has beenndesigned. Measurements show very interesting frequency performance (fn0 tunable in the range 30-120 MHz and Q from 1-140) innconjunction with low power consumption (25 mW for the fourth-ordernfilter with ±2.5 V supplies)