A wideband distributed mixer capable of operation over a wide range of frequencies is provided. The mixer can include a plurality of N mixer stages and monolithic transmission lines integrated together on a common semiconductor substrate. The length of each transmission line between adjacent stages can be predetermined such that an IF signal output from each stage is in-phase with the IF signal output from any preceding stage, allowing the mixer to output a mixed IF signal that is a constructive sum of the IF output signals from each constituent stage. The number of mixer stages as well as the design architectures and topologies for each stage can be varied according to the needs of the application.