Mixer circuit

A CMOS passive mixer circuit for mixing an input signal with a frequency signal comprising a plurality of transistors, wherein at least one transistor of the plurality of transistors is arranged to receive a drive signal output from a driver circuit, the driver circuit comprising:

• a first circuit branch having first and second circuit components arranged to receive respectively the input signal and a control signal;
• a second circuit branch having first and second circuit components, the first component arranged to receive the input signal;
• and
• an operational amplifier having a first input connected to a junction node of the first and second circuit components of the first circuit branch and a second input connected to a junction node of the first and second circuit components of the second circuit branch, the operational amplifier arranged to provide an operational amplifier output signal to the second component of the second circuit branch so that a voltage at the junction node of the several circuit branch is equal to a voltage at the junction node of the first circuit branch, said voltage dependent on said input signal and providing said drive signal to the at least one transistor.