Abstract: The integrated circuit includes a power amplifier intended to provide a signal in a fundamental frequency band, an antenna, and a matching and filtering network having a first section, a second section, and a third section. The three sections include LC arrangements configured to have an impedance matched to the power amplifier's output in the fundamental frequency band. The LC arrangements of the first section and the second section are configured to have resonant frequencies adapted to attenuate the harmonic frequency bands of the fundamental frequency band.

Abstract: The integrated circuit includes a power amplifier, an antenna, and a matching and filtering network including a direct current power supply stage on an output node of the power amplifier, a first section, and a second section. The direct current power supply stage and the two sections include inductor-capacitor “LC” arrangements configured to have an impedance that is matched to the output of the power amplifier in the fundamental frequency band. The LC arrangements of the direct current power supply stage and of the first section are furthermore configured to have resonant frequencies that are respectively adapted to attenuate harmonic frequency bands of the fundamental frequency band.

Abstract: According to one aspect, an integrated circuit includes a power amplifier having a succession of at least two amplifier stages. The two amplifier stages include a first amplifier stage configured to receive a radio frequency signal as input and a last amplifier stage configured to deliver as an output of an amplified radio frequency signal. The power amplifier further includes a safety circuit with a control circuit configured to compare the amplified radio frequency signal voltage with a threshold voltage. The safety circuit further comprises a gain reduction circuit configured to reduce a bias voltage of an upstream amplifier stage of the last amplifier stage when the amplified radio frequency signal voltage is greater than the threshold voltage.

Abstract: Cancellation of a leaked transmission signal received together with a received signal is cancelled at a receiver amplifier in a system made up of the receiver amplifier, a power amplifier, and a duplexer that couples both to an antenna. A portion of the amplified transmission signal from the power amplifier is split off prior to the duplexer. That portion is controllably applied to the receiver amplifier. A feedback loop monitors the amplified output of the receiver amplifier and varies the gain and phase of the portion of the amplified transmission signal in order to minimize the amount of transmission signal in the amplified output of the receiver amplifier.

Abstract: A signal cancelling duplexer is provided. Duplexers of the invention add equal amounts of a transmission signal and an out-of-phase component of the same transmission signal at the receiver, so that both signals cancel. Duplexers of the invention can be switched between multiple channels by changing switch settings within the duplexer. RF transceivers including a power amplifier, receiver amplifier, and the signal cancelling duplexer are also provided.

Abstract: Switches comprising a number of transistors in series achieve improved performance through biasing the bodies of the transistors to lower the stack resistance in the ON mode and optionally to also lower the stack capacitance in the OFF mode. These switches find use in RF applications such as phase shifters, step attenuators, and in antenna switches, for example. In some embodiments, a bias network is used to alternatingly provide a positive bias voltage or a negative bias voltage to the bodies of the transistors.