Patent ID: 8493136

Claim:
A driver circuit for supplying a drive signal to a mixer circuit, the driver circuit comprising: a first circuit branch having first and second circuit components arranged to receive respectively an input signal and a bias signal, wherein the bias signal is variable to control the linearity of the driver circuit; 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 second 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.