Abstract: A method of providing an input signal to a mixer circuit comprises coupling an output signal from a low-noise amplifier circuit to a mixer input of the mixer circuit via an AC coupling circuit, comprising an inductive of capacitive coupling circuit. For capacitive coupling configurations, a coupling capacitor is configured to have a capacitance value determined as a function of a transconductance sensitivity of the mixer circuit. For balanced output configurations of the low-noise amplifier circuit, matched coupling capacitors are used for coupling the balanced output signals to respective inputs of the mixer circuit. In one embodiment, the mixer circuit comprises a quadrature mixer circuit, which may be in a balanced or double-balanced configuration. In another embodiment, the mixer circuit comprises a four-phase mixer circuit, which may be configured as a balanced four-phase mixer circuit coupled to the low-noise amplifier circuit via inductive or capacitive embodiments of the coupling circuit.

Abstract: A method of providing an input signal to a mixer circuit comprises coupling an output signal from a low-noise amplifier circuit to a mixer input of the mixer circuit via an AC coupling circuit, comprising an inductive of capacitive coupling circuit. For capacitive coupling configurations, a coupling capacitor is configured to have a capacitance value determined as a function of a transconductance sensitivity of the mixer circuit. For balanced output configurations of the low-noise amplifier circuit, matched coupling capacitors are used for coupling the balanced output signals to respective inputs of the mixer circuit. In one embodiment, the mixer circuit comprises a quadrature mixer circuit, which may be in a balanced or double-balanced configuration. In another embodiment, the mixer circuit comprises a four-phase mixer circuit, which may be configured as a balanced four-phase mixer circuit coupled to the low-noise amplifier circuit via inductive or capacitive embodiments of the coupling circuit.