Temperature and process compensating circuit and controller for an RF power amplifier

A radio frequency (RF) power amplifier circuit comprising:

• an RF gain stage formed on an integrated circuit (IC) chip comprising at least one field effect transistor configured for amplifying an RF signal to provide an amplified RF signal to an antenna at a given RF power level;
• a compensation circuit formed on said IC chip for generating a first voltage VS+ and a second voltage VS− at respective first and second output terminals thereof, the voltage difference therebetween corresponding to a level of temperature or process fluctuation associated with said RF gain stage from a given level;
• and
• a control circuit comprising an operational amplifier coupled to the first and second output terminals of said compensation circuit for receiving said first and second voltages VS+, VS− and outputting a control signal to the gate of said at least one FET of said RF gain stage to compensate said RF gain stage for said fluctuation, whereby a substantially constant power output to said antenna is maintained.

An RF power amplifier circuit comprising:

• a plurality of FET amplifiers coupled together in a cascaded configuration for amplifying an RF signal to provide an amplified RF signal at an output terminal and at a given power;
• a sensing circuit comprising a FET amplifier having temperature characteristics similar to those of said plurality of FET amplifiers, said sensing circuit positioned adjacent said plurality such that said sensing circuit is affected by temperature fluctuations in said plurality of FET amplifiers, said sensing circuit having first and second output terminals for outputting first and second voltage signals respectively which correspond to a differential voltage indicative of the sensed difference in temperature from a given level of said plurality of FET amplifiers;
• and
• a control circuit comprising an operational amplifier for receiving said first and second differential voltage signals and responsive to a variable input control voltage for providing an output control signal to at least one gate electrode of said plurality of FETs to cause a change in output characteristics of said plurality to compensate for said sensed temperature fluctuation.

A power amplifier circuit comprising:

• an RF gain stage formed on an integrated circuit (IC) for providing an amplified RF signal at an output terminal thereof;
• a compensation circuit formed on said IC chip for generating a first voltage and a second voltage at respective first and second output terminals thereof, the voltage difference therebetween corresponding to a level of fluctuation associated with said RF gain stage from a given level;
• and
• a control circuit comprising an operational amplifier coupled to the first and second output terminals of said compensation circuit for receiving said first and second voltages and outputting a control signal to said RF gain stage to compensate said RF gain stage for said fluctuation.

An amplifying apparatus comprising:

• an RF gain stage for providing an amplified RF signal at an output terminal thereof;
• a sensor circuit for generating a differential voltage signal indicative of a fluctuation in temperature of said RF gain stage from an ambient value;
• and
• a control circuit comprising an operational amplifier responsive to said differential voltage signal and to an at least one input control signal for providing a control signal to said RF gain stage to compensate said RF gain stage for said temperature fluctuation to maintain a substantially constant power output at said output terminal.