Patent ID: 7633328

Claim:
A mixer stage comprising: an oscillator; a first input; a second input; a first output; a second output; a set of four controllable amplifier elements; and a set of four switchable current sources and two resistors for the set of four controllable amplifier elements, wherein a first pair of said set of four switchable current sources and a second pair of said set of four switchable current sources are each being switched on and off by an associated switching input that is connected to an associated oscillator output, wherein pairs of amplifier elements of the set of four controllable amplifier elements, with at least one of the first and second pair of current sources in its switched-on state, form a differential amplifier for an input signal present at the first input and the second input, and wherein each of the set of four switchable current sources is connected in series to one of the set of four controllable amplifier elements, and wherein said first pair of switchable current sources is connected by a first resistor of the two resistors and said second pair of switchable current sources connected by a second resistor of the two resistors.