Frequency mixer topology providing high linearity, low noise and high gain

Frequency conversion circuitry having an input node for receiving an input signal at a first frequency and an output node for producing an output signal at a second frequency different from the first frequency, the circuitry comprising:

• a switching/commutating mixer circuit responsive to the input signal for producing a signal at the second frequency,
• a step down impedance transformation circuit coupled between the input node and an input of the mixer circuit for providing input impedance of the mixer circuit lower than impedance at the input node, and
• a common-base or common-gate amplifier circuit having low input impedance coupled between an output of the mixer circuit and the output node for amplifying the signal at the second frequency produced at the output of the mixer circuit, the mixer circuit being configured for providing input impedance of the output amplifier lower than the impedance at the input node.