The HMC560 chip is a miniature passive double balanced mixer which is fabricated in a GaAs MESFET process, and can be used as an upconverter or downconverter from 24-40 GHz in a small chip area. The wide bandwidth allows this device to be used across multiple radio bands with a common platform. Excellent isolations are provided by on-chip baluns, and the chip requires no external components and no DC bias. Measurements were made with the chip mounted and ribbon bonded into in a 50-ohm microstrip test fixture. Measured data includes the parasiticeffects of the assembly. RF connections to the chip were made with 0.076mm (3-mil) ribbon bond with minimal length <0.31mm (<12 mil).