A monolithic RF amplifier circuit (10) suitable for use in the 0.8-2 GHz frequency range comprises, on-chip (12'), a gateable oscillator (24) running at about 2-5 times the amplifier input frequency or higher, coupled to a rectifier (30) and a low pass filter (34) for producing a DC signal which is fed via a bias/gain control circuit (46) to a bias/gain inputs (56, 58) of one or more amplification stages (60, 62) (e.g. GaAs FET) to provide bias therefore to ensure safe operation, and a priority control circuit (42) responsive to the bias. The priority control circuit (42) operates a power switch (18) that couples the amplification stages (60,62) to a power supply, only when bias is present on their bias/gain inputs (56,58) This protects the amplification stages (60,62) against overcurrent operation. A separate external port (68) to the bias/gain control circuit (46) adjusts the magnitude of the bias to permit amplifier gain and power output to be adjusted. By gating the oscillator ON and OFF, high speed burst mode operation of the amplifier is achieved.