For example: Agilent E4440A or Anritsu 68369
Amplifier Research
Amplifier Research 75A250A
75W CW, 10Khz-250Mhz, Amplifier (w/ DCP, IEEE & RS-232 interfaces)
Category: Amplifiers
Amplifier Research DC7144A
0.8 - 4.2 GHz, 400 Watt, Dual Directional Coupler (40dB) (for models 5S1G4, 20S1G4, 40S1G4, 80S1G4, 175S1G4)
Category: Accessory
Amplifier Research FP5031
FIELD MONITOR PROBE
Category: Probes (Scope, Meters, Logic and Spectrum Analyzers)