High dynamic range mixers are becoming more important as the complexity of the electronic warfare systems increase. Since it is usually the first or second device from the rf input, the performance of the mixer is critical in the overall operation of the system. The design of the present day mixers in the millimeter wavebands are based on schottky based diodes in the self bias mode and advancement in the double balanced structures has been either non-existent or very slow and uneconomical. The double balanced structure offers the best performance as far as the rejections of the input signals and intermodulation performance is concerned. The limiting factor of the mm wave double balanced structure is the design of the passive balun. This proposal will detail a high dynamic mixer design, together with a detailed balun design.