Abstract:
A radio-frequency switching device includes first and second radio-frequency channels connected to an input/output terminal. A controllable switching device selects one of the radio-frequency channels in response to a switching control signal. The switching device includes a respective control module connected to each radio-frequency channel. Each control module includes a PIN diode whose cathode is connected to the input/output terminal, and a control transistor whose base is connected to a control input for receiving the switching control signal. A conducting terminal of the control transistor is connected to the anode of the PIN diode.
Abstract:
A direct-conversion receiver includes an analog stage for receiving an incident signal from a transmission channel, mixers and programmable-gain amplifiers. The receiver further includes at least one compensation module having input and output terminals respectively connected between the output of the mixers and the input of the programmable-gain amplifiers. The compensation module compensates for both a static DC voltage offset and a possible dynamic DC voltage offset of the analog stage.
Abstract:
A cellular telephone includes a plurality of power amplifiers having a common operating region. If one of the amplifiers has to be deselected, a desired moment for the switching to another amplifier is defined based upon a predetermined transmission interrupt criterion. The power continues to be adjusted with the currently selected amplifier until the instant of switch over. Switching to the other amplifier may then be performed after the transmission has been interrupted.