Low Power and Wide Gain‐Range Mixer Using Current‐Bleeding Variable‐Gain Amplification

ABSTRACT This paper presents a mixer with low power and a wide gain‐range using a current‐bleeding variable‐gain amplifier (VGA) technique. The proposed 2.4‐GHz mixer controls the conversion gain by replacing a conventional current‐bleeding stage with the VGA while maintaining the low‐power function of current‐bleeding. The VGA is composed of a common‐source (CS) amplifier, a current controller, and a variable load. It has a wide variable‐gain range by changing transconductance ( g m ) of the CS amplifier and output resistance of the variable load stage. The proposed mixer is fabricated in 65‐nm CMOS process. The measured results showed a conversion gain of 20.5 dB, a variable‐gain range of more than 45 dB, a third‐order input‐intercept point (IIP3) of −14.4 dBm, and power consumption of 5.4 mW at a 1.2‐V supply voltage.