Abstract: The invention relates to a communication system comprising a first and a second communication device, each comprising transmit and receive units for establishing a wireless link between the devices, wherein the first device is a portable listening device. The invention further relates to a method, a data processing system and a medium. The object of the present invention is to control power consumption in a short range wireless link. The problem is solved in that at least the first communication device comprises a control unit for dynamically adjusting the transmit power of its transmit unit based on a measure of the quality of the link, wherein the system is adapted to use the dynamic transmit power regulation to implement a partial power-down mode of the system, when the two communication devices are expected NOT to be in a normal use, wherein the partial power-down mode at least comprises a power-down of the components related to the wireless link.

Abstract: The invention relates to a communication system comprising a first and a second communication device, each comprising transmit and receive units for establishing a wireless link between the devices, wherein the first device is a portable listening device. The invention further relates to a method, a data processing system and a medium. The object of the present invention is to control power consumption in a short range wireless link. The problem is solved in that at least the first communication device comprises a control unit for dynamically adjusting the transmit power of its transmit unit based on a measure of the quality of the link, wherein the system is adapted to use the dynamic transmit power regulation to implement a partial power-down mode of the system, when the two communication devices are expected NOT to be in a normal use, wherein the partial power-down mode at least comprises a power-down of the components related to the wireless link.

Abstract: An amplifier circuit includes a bias control feedback loop. A sensing transistor (105) is matched to one or more power transistors (101a, 101b, 101c) and is correspondingly biased. The difference between collector voltage of the sensing transistor (105) and a reference voltage amplified by a differential amplifier (111, 114) provides the base bias voltage for the power transistors (101a, 101b, 101c) and the sensing transistor (105). The gain of the amplifier is controlled by applying a control voltage to a resistor (110) connected to the collector of the sensing transistor (105).

Abstract: A circuit interfacing a balanced RF power amplifier with unbalanced load has a first shunt inductor and a series capacitor connected to a first output and a first shunt capacitor and series inductor connected to a second output of amplifier. The circuit comprises a second shunt inductor connected to the second output and feeding current to the second output. The first shunt capacitor may correspond to a sum of capacitors required to resonate with the series inductor and second shunt inductor. The second shunt inductor may exceed a value required to resonate with the capacitance of the first shunt capacitor less the capacitance required to resonate with the series inductor, by the same amount as the first shunt inductor exceeds the value required to resonate with the series capacitor. The circuit may further comprise a second shunt capacitor connected to first output, whereby first shunt capacitor exceeds sum of capacitors required to resonate with series inductor and second shunt inductor.

Abstract: An amplifier circuit includes a bias control feedback loop. A sensing transistor (108) is matched to one or more power transistors (101a, 101b, 101c) and is correspondingly biased. The difference between collector voltage of the sensing transistor (108) and a reference voltage amplified by a differential amplifier (111, 114) to provide the base bias voltage for the power transistors (101a, 101b, 101c) and the sensing transistor (105). The gain of the amplifier is controlled by applying a control voltage to a resistor (110) connected to the collector of the sensing transistor (105).

Abstract: A circuit interfacing balanced RF Power Amplifier with unbalanced load has first shunt inductor and series capacitor connected to first output and first shunt capacitor and series inductor connected to second output of amplifier, and comprises second shunt inductor connected to second output and feeding current to this output.