The new CMOS 2 V low-power IF fully differential Rm-C bandpass amplifier for RF wireless receivers

A new CMOS fully differential bandpass amplifier (BPA) based on the structure of a transresistance (Rm) amplifier and capacitor is proposed and analyzed. In this design, the Rm amplifier is realized by a simple inverter with tunable shunt-shunt feedback MOS resistor and tunable negative resistance realized by the cross-coupled MOS transistors in parallel with a current source. The capacitor is in series with the input of the Rm amplifier, which realizes the filter function and blocks the DC voltage. Under a 2 V supply voltage, the post-tuning capability of the gain can be as high as 90 dB whereas the tunable frequency range is between 41 MHz and 178 MHz. The power consumption is 11 mW and the dynamic range (DR) is 50 dB. The differential-mode gain is 20 dB and the common-mode gain is -25 dB so that the CMRR is 45 dB. Simple structure, good frequency response and low power dissipation make the proposed bandpass amplifier guite feasible in the applications of an IF stage for RF receivers