For example: Agilent E4440A or Anritsu 68369
Pulse Generators
Keithley Instruments 3401F
165MHz Single-Channel Pulse Generator, Front Connector

Manufacturer: Keithley Instruments
Keithley Instruments 3401R
165MHz Single-Channel Pulse Generator, Rear Connector

Manufacturer: Keithley Instruments
Keithley Instruments 3402F
KEITHLEY 3402-F SIGNAL GENERATOR, 2-CHANNEL

Manufacturer: Keithley Instruments
Keithley Instruments 3402R
165MHz Dual-Channel Pulse Generator, Rear Connector

Manufacturer: Keithley Instruments
Keysight / Agilent 81110A
Agilent 81110A Pulse Pattern Generator, 165/330 MHz

Manufacturer: Keysight / Agilent
Keysight / Agilent 81134A
81134A Pulse Pattern Generator, 3.35 GHz, dual-channel

Manufacturer: Keysight / Agilent
Keysight / Agilent 8114A
HP Agilent 8114A Programmable Pulse Generator, 15MHz

Manufacturer: Keysight / Agilent
Keysight / Agilent 8114A-001
HP Agilent 8114A Programmable Pulse Generator, 15MHz

Manufacturer: Keysight / Agilent
Keysight / Agilent 8115A
Agilent 8115A 50MHz DUAL CHANNEL PULSE GENERATOR

Manufacturer: Keysight / Agilent
Keysight / Agilent 8133A
HP Agilent Keysight 8133A Pulse Generator, 15 MHz - 3.35 GHz

Manufacturer: Keysight / Agilent
Keysight / Agilent 8133A-002
HP Agilent Keysight 8133A Pulse Generator, 15 MHz - 3.35 GHz w/ Option 002

Manufacturer: Keysight / Agilent