Intermodulation performance enhancement by dynamically controlling RF amplifier current

摘要

An improved radio receiver includes a signal input terminal (105), a variable-current RF signal amplifier (109), a demodulator (127), and a controller (135). The variable-current RF signal amplifier has an input terminal (107) for accepting RF input signals, an output terminal (117) for generating an amplified version of the RF input signals, and a current control terminal for controlling the current consumption of the RF signal amplifier. In response to signals amplified by the RF signal amplifier (109) and demodulated by the demodulator (127), the controller (135) controls (via 113) the current consumed by the variable-current RF signal amplifier to achieve at least a minimum acceptable signal-to-interference ratio for a desired signal, while the Noise Figure is not degraded any more than is necessary to achieve a minimum acceptable signal-to-interference ratio at any given time. In this manner, the variable current RF signal amplifier (109) is adjusted to obtain a required amount of intermodulation performance for a given set of receiving conditions. This technique saves operating current and maintains fade margins because, in practice, interference conditions do not persist all of the time, and are usually of temporary duration.