A sub-harmonic mixer two or more cascaded stages for converting a Radio Frequency signal to an Intermediate Frequency signal. Each stage comprises a common-emitter transistor or a common-source transistor and each stage having an input and an output, the output of each stage is coupled to the input of a next stage by a capacitor. An Alternating Current choke is coupled at a collector or drain of each transistor. An LO input is coupled to the input of a first stage of the two or more stages; an RF input is coupled to the output of the first stage of the two or more stages; and an IF output is coupled to the output of a last stage of the two or more stages.

An up-conversion mixer includes a mixer cell having at least one output node configured to generate an output. The up-conversion mixer further includes an input stage coupled to the mixer cell, the input stage configured to receive an input signal and to produce a local minimum in a third order harmonic of the output with respect to an input power. The up-conversion mixer further includes a power supply input configured to receive a power supply voltage and a ground, and a maximum number of transistor stages between the power supply input and the ground is two.