Demonstration circuit 910A is optimized for evaluation of the LT5557 active downconverting mixer with discrete IF output balun for lower cost applications. Its RF input and LO input ports are internally matched to 50W, from 1.6 to 2.3GHz, and from 1 to 5GHz, respectively. The IF output is 50W matched to 240MHz using a discrete balun. Compared to the transformer-based matching technique, the discrete balun approach yields narrower IF output bandwidth, higher conversion gain, and slightly degraded IIP3 and noise figure. The LT5557 active mixer is optimized for high linearity, wide dynamic range downconverter applications. The IC includes a high-speed differential LO buffer amplifier driving a double-balanced mixer. Broadband, integrated transformers on the RF and LO inputs provide single-ended 50W interfaces. The differential IF output allows convenient interfacing to differential IF filters and amplifiers, or is easily matched to drive a singleended 50W load, with or without an external transformer. The LT5557?s high level of integration minimizes the total solution cost, board space and system-level variation.