For example: Agilent E4440A or Anritsu 68369

AC Power Supplies

Programmable AC Power Sources, Frequency Converters

Manufacturers: California Instruments, California Instruments-Ametek, Chroma, Digital Electronics, Pacific Power Source, Ametek - Elgar, Elgar, Keysight / Agilent, Kikusui, TDK-Lambda, Instek, Sorensen, Xantrex, Associated Power Technologies, Transistor Devices, BK Precision, IET, Keithley Instruments, Fluke, Tennelec, Behlman Electronics, Steelman Industries, Inc., Haefely, NHR, Anritsu, Quadtech, XPPOWER