Abstract: A portable radio transceiver has a transmitter power amplifier (PA) and a series transistor (V1), which is connected to the transmitter power amplifier and is adapted, in response to a transmission control signal (TX on/off), to control transmission by the transmitter power amplifier. Negative bias generating means provides negative bias (Vneg) to the transmitter power amplifier and is also used for increasing a voltage applied to the gate of the series transistor so as to reduce its resistance. The negative bias generating means has a second transistor (V2) connected to the gate of the series transistor (V1), and a third transistor (V3), the gate of which is adapted to receive the transmission control signal (TX on/off) It also has a capacitor (C1) connected between the second and third transistors, and a diode means (D1) connected between the capacitor and the second transistor.

Abstract: A memory card receptacle 20 comprising at least one contact 30 (37, 38) for electrically contacting a memory card 18. The memory card receptacle 20 has at least one grounding contact member 36, for protecting electronic equipment 10 against electro static discharge (ESD), whereat each contact 30 (37, 38) is in contact with said grounding contact member when there is no memory card 18 inserted in the memory card receptacle 20. A portable radio communication station having SIM chip card reader according to the invention is disclosed.

Abstract: A shielding device is formed by a wall having a top edge arranged to fasten a foil comprising an electrically conducting material. In order to fasten the foil, the wall can be provided with teeth at its top section. Also the wall(s) can be formed with arbitrary angles with respect to each other when forming a whole shielding device. The cover can be formed by one large or several smaller pieces. The cover is fastened to the walls by means of an adhesive, glue or soldering and an electrical contact is provided by the teeth projecting from the wall(s).

Abstract: A memory card receptacle 20 comprising at least one contact 30 (37,38) for electrically contacting a memory card 18. The memory card receptacle 20 has at least one grounding contact member 36, for protecting electronic equipment 10 against electro static discharge (ESD), whereat each contact 30 (37,38) is in contact with said grounding contact member when there is no memory card 18 inserted in the memory card receptacle 20. A portable radio communication station having SIM chip card reader according to the invention is disclosed.

Abstract: A device for performing voltage conversion in an integrated circuit comprising a plurality of different components, one or more of which requires a voltage which differs from the supply voltage of the integrated circuit has two circuits. The first circuit is designed to convert a first voltage into an optical signal, which is emitted from at least one element in the first circuit. The second circuit has one or more photosensitive elements, which are designed to receive the optical signal and convert the optical signal into a second voltage that is different and electrically isolated from the first voltage.