The 37000 family millimeter wave vector network analyzer (VNA) extends the exceptional performance of the Lightning VNA family to 140 GHz. This improvement to our original millimeter wave system, based on the 360B VNA, continues our commitment to providing the highest quality microwave and millimeter wave test equipment available while still maintaining an intuitive user interface. The minimum configuration for the millimeter wave VNA has a 37147A VNA, a 3735B Test Set, two synthesized sources, and a pair of millimeter heads.