Patent ID: 7345545

Claim:
A switched gain RF amplifier having an RF IN port, an RF OUT port and two or more control ports, comprising: a first RF amplifier having a first input coupled to the RF IN port and having a first output; a second RF amplifier having a second input and having a second output coupled to the RF OUT port; an RF switched attenuator (RF SW AT) having an RF signal input port coupled to the first output and an RF signal output port coupled to the second input, wherein the RF SW AT comprises; first and second n-channel enhancement mode FETs, each having source, drain and multiple parallel-coupled gate regions serially arranged and spaced apart between the source and drain; wherein the source of the first FET is coupled to the RF signal input port of the RF SW AT and the drain of the first FET is coupled to the RF signal output port of the RF SW AT and the multiple parallel-coupled gate regions of the first FET are coupled to a first of the two or more control ports; first and second resistances commonly connected at a first common node and serially coupled between the source and drain of the first FET; a reference potential connection; a third resistance having a first terminal coupled to the reference potential connection and having a second terminal; wherein the source of the second FET is coupled to the second terminal of the third resistance and the drain of the second FET is coupled to the first common node and the multiple parallel-coupled gate regions of the second FET are coupled to a second of the two or more control ports.