Radio frequency amplifier having improved ctb and cross modulation

Abstract

A radio-frequency amplifier circuit of simple construction having low power consumption and low heat generation and which amplifies an input signal while maintaining composite triple beat (CTB) distortion, type cross modulation distortion at a minimum, is provided. The radio-frequency amplifier comprises a transformer which transforms an input signal from an unbalanced state to a balanced state. The amplifier further comprises at least one distortion generation circuit including a first circuit having a nonlinear element and a first delay line coupled in series, and a second circuit having an attenuation element and a second delay line coupled in series. The first and second circuits are coupled in parallel. At least one distortion generation circuit is coupled to an input, an output, and/or an intermediate point of a radio-frequency amplification stage of the radio-frequency amplifier. The first and second delay lines are configured to create a delay time change in a signal input level of a signal input to the radio-frequency amplification stage which opposes a delay time change in the signal input level caused by a delay time difference between the input and output of the radio-frequency amplification stage. A transformer transforms the amplified input signal from the balanced state back to an unbalanced state before outputting the amplified signal from the amplifier circuit.