Abstract: A single balanced mixer covering full W-band was designed for a hardware in the loop (HIL) simulation system to achieve large bandwidth and dynamic range. The mixer was designed with waveguide-quartz hybrid circuit and a discrete Schottky diode. Two Schottky junctions were excited in-phase with the radio frequency (RF) signal through height-reduced waveguide, so the additional loss of passive circuits can be reduced. With E-plane probe, the local oscillator (LO) signal was coupled with quasi-TEM mode, thus the two Schottky junctions were driven out of phase. The measured single sideband (SSB) loss is 6~8dB over the 75~110GHz range with 13dBm LO power, and the intermediate frequency (IF) bandwidth is DC~35GHz. The mixer has comparable technical performance with similar high-performance products at home and abroad, and has been successfully applied in the W-band HIL simulation systems.