Power amplifier self-heating compensation circuit

An integrated circuit including (1) a pulsed-operation amplifier having a Gain that droops due to heating of the amplifier during operation, and (2) a temperature compensation circuit, the temperature compensation circuit including:

• (a) at least one sensor located with respect to the amplifier so as to measure the temperature of the amplifier and generate an output signal T representing such temperature;
• (b) at least one sample and hold circuit, each coupled to at least one sensor through an intermediate amplifier coupled between the at least one sensor and the at least one sample and hold circuit, configured to capture a temperature T(t=t0) at a time t0 after commencement of operation of the amplifier, and to sample a temperature T(t>t0) at times after time t0 during operation of the amplifier;
• (c) a comparison circuit, coupled to at least one sample and hold circuit, for determining a signal ΔT=T(t>t0)−T(t=t0);
• and
• (d) a mapping circuit, coupled to the comparison circuit, for receiving values of the signal ΔT and mapping the values of the signal ΔT to corresponding control signal values, the control signal values being coupled to one or more adjustable circuits on the integrated circuit to adjust one or more circuit parameters of the one or more circuits, wherein the mapping circuit converts the values of the signal ΔT to digital values and applies the digital values to a look-up table programmed with a desired mapping function in order to generate corresponding control signal values in digital form.

An integrated circuit including (1) an amplifier having a Gain that droops due to self-heating of the amplifier during operation, and (2) a temperature compensation circuit, the temperature compensation circuit including:

• (a) at least one sensor located with respect to the amplifier so as to measure the temperature of the amplifier due to self-heating and generate an output signal T representing such temperature;
• (b) at least one sample and hold circuit, each coupled to at least one sensor through an intermediate amplifier coupled between the at least one sensor and the at least one sample and hold circuit, configured to capture a temperature T(t=t0) at a time to after commencement of operation of the amplifier, and to sample a temperature T(t>t0) at times after time to during operation of the amplifier;
• (c) a comparison circuit, coupled to at least one sample and hold circuit, for determining a signal ΔT=T(t>t0)−T(t=t0);
• and
• (d) a mapping circuit, coupled to the comparison circuit, for receiving values of the signal ΔT and mapping the values of the signal ΔT to corresponding control signal values, the control signal values being coupled to one or more adjustable circuits on the integrated circuit to adjust one or more circuit parameters of the one or more circuits sufficient to substantially offset the effect of self-heating on the Gain of the amplifier during operation of the amplifier.