Nokia Mobile Phones Limited

Toivo Vilmi

Jaakko A Hulkko

Aki Leppanen

Jorma Matero

Jarmo J Heinonen

Hands free equipment for mobile phones, has an extra loudspeaker and microphone and an electronic unit included therein, the equipment being mainly intended for use in cars, whereby driving safety is maintained. The equipment Is connected to the charger of the cigarette lighter. The hands free equipment according to the invention consists of a separate, small-sized, detachable and movable unit situated outside the mobile phone.

Hands free equipment

Hands free equipment for mobile phones, has an extra loudspeaker and microphone and an electronic unit included therein, the equipment being mainly intended for use in cars, whereby driving safety is maintained. The equipment is connected to the charger of the cigarette lighter. The hands free equipment according to the invention consists of a separate, small-sized, detachable and movable unit situated outside the mobile phone.

A method of controlling an external radio frequency amplifier of a radio telephone and a control system therefore. The power amplifier of the transmission side of the radio frequency amplifier is controlled to turn on and off, on the basis of at least one control signal (BENA1, BENA2) entering the radio frequency amplifier separate from a signal to be transmitted from the radio telephone. The control signal (BENA1, BENA2) contains information about the starting and ending instant of transmission.

Amplifier control system

A dual mode transmitter circuit is disclosed including a non-linear high-power amplifier having an amplification that can be adjusted and a linear high-power amplifier. A first switch and a second switch are connected to the input and output of the linear, high-power amplifier. An amplification-adjustable, high-frequency transmitter control amplifier is connected to the input of the non-linear high-power amplifier. Apparatus for measuring transmission power such as a directional coupler is connected to the second switch, and a duplex filter is connected to the directional coupler. A power level control circuit is responsive to the measured transmission power from the directional coupler and to a power level signal. The power level signal is representative of the desired output power of the transmitter. The power level control circuit compares the measured power level from the directional coupler with the desired power level and produces a difference signal on its output lead which is connected to both the non-linear high-power amplifier and to the high-frequency transmitter control amplifier. A mode selection signal, for designating either an analog or digital type transmission mode is applied to a mode control circuit that is responsive to the mode selection signal and provides switching signals to the first and second switches and a control signal to the linear amplifier. The mode selection signal sets the transmitter to function in either the non-linear transmission (analog) mode or the linear transmission (digital) mode.

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Haukipudas, Finland

Toivo Vilmi