The Model 870A signal generator reaches 12.75, 20, 40 or 54 GHz from a 10 MHz start, with an option extending coverage down to 9 kHz. It delivers one to four phase-coherent channels in a desktop unit or 2U rackmount. Phase noise at 1 GHz is -132 dBc/Hz at 1 kHz offset, and Option FS cuts list-mode switching to 15 µs. Use it as a low-noise R&D source, in production ATE, or for radar simulation.