The invention, which belongs to the
radio frequency integrated circuit design technology field, more particularly relates to a
Gilbert cell mixer with automatic optimal bias and
harmonic wave control. The mixer comprises a basic Gilbert
frequency mixing unit, an optimal bias circuit and a
harmonic wave
control circuit. The Gilbert
frequency mixing unit consists of a
transconductance level, a switch level, and a load level. The optimal bias circuit includes duplication or reduction with a same proportion of a
transconductance-level device of the Gilbert
frequency mixing unit, a
resistor chain, and operational amplifiers, wherein weak currents flow through the
resistor chain and the operational amplifiers form two feedback loops. A middle point of the
resistor chain in the optimal bias circuit provides a
direct current bias for a
transconductance tube in the Gilbert frequency mixing unit. And the
harmonic wave
control circuit is composed of an adjustable active
inductance and a harmonic wave control
capacitor; and the harmonic wave
control circuit is connected to a drain terminal of the transconductance tube of the Gilbert frequency mixing unit. According to the invention, accuracy of a generated optimal bias is optimized; and a secondary harmonic wave
feedback effect is overcome. Besides, the
Gilbert cell mixer with automatic optimal bias and harmonic wave control is suitable for application to a
wireless communication
transceiver circuit needing an
active mixer with high
linearity.