For example: Agilent E4440A or Anritsu 68369
Function Generators
Tektronix AWG710B
Tektronix AWG710B 4.2GS/s 1CH Arbitrary Waveform Generator Arbitrary Waveform Generator
Manufacturer: Tektronix
Tektronix AWG7121B
12GS/s, 1ch, 10bits, 32M point/ch Arbitrary Waveform Generator
Manufacturer: Tektronix
Tektronix AWG7122B-08
12GS/s, 2ch, 10bits, 32M point/ch Arbitrary Waveform Generator
Manufacturer: Tektronix
Stanford Research Systems CG635
Stanford Research CG635 Synthesized Clock Generator, 2.05 GHz
Manufacturer: Stanford Research Systems
Stanford Research Systems DS345
DS345 30 MHz function/ARB generator
Manufacturer: Stanford Research Systems