Abstract: A method for providing a positive transmitter power switch-on in a dual-mode mobile phone is disclosed. According to the invention the transmitter is switched on in two or more phases, controlled by the mobile phone microprocessor program. Preferably the power amplifier sections are switched on in a sequence, so that the output power amplifier sections (3 and 4) are first switched on by enabling the transmit enable signal (TXE). Then the input power amplifier sections (1 and 2) are switched on by enabling ramp-up signal (RAMP-UP) Transmission is thereafter enabled by the transmit power control signal (TXC) being switched on, the amplifiers then output the amplified radio frequency input signal (RFIN) to the duplex circuit (10) transmit terminal (TX).

Abstract: An earthed intermediate frame (2) fitted between circuit boards (1) is provided with through apertures (8) for connectors (4) connecting the circuit boards (1), and grooves (6) are provided in register with the signal runs (5) on the surface of the circuit board (1), located on the surface of the intermediate frame (2) placed against the surface of the circuit board. The intermediate frame made of a metal or the surfaces of the apertures (8) surrounding the connectors (4) connecting the circuit boards (1) and of the grooves (6) covering the signal runs (5) of the circuit board (1) have been coated with an earthed metal folio (7).