Temperature-compensated directivity control in power amplifier modules

Abstract

Systems and methods for temperature-compensated directivity control in a power amplifier module that includes a directional coupler coupled to a power amplifier is presented. A termination resistance having a temperature profile that varies with temperature is coupled to an isolation port of the directional coupler. The temperature profile is predetermined and based on measured and/or simulated data representing variation of directivity of the power amplifier module with temperature. The temperature profile is further based on measured and/or simulated correlation data between directivity and termination resistance. According to one aspect, the termination resistance is provided by one or more FETs whose gate voltages are controlled via a feedback loop that includes a bandgap voltage reference and a temperature-dependent current source. According to another aspect, the termination resistance is provided by one or more composite resistors, each composite resistor including at least two resistors with different temperature coefficients.

Dependencies are inferred from the claim text.