Nokia Mobile Phones Limited

Pertti J Korhonen

Raimo K Kivari

Mikko Veijo Halttunen

Seppo Salonen

Kalle J Korhonen

An assembly and method of assembly for shielding a radio telephone. First and second shields are disposed either side of a circuit board and urged together thereby sandwiching the circuit board. The first shield is relatively rigid compared to the second shield and can cause any deformities in the second shield to be compensated for by the second shield being urged against a rigid first shield, the shields may be removably coupled together which permits simple and quick disassembly if changes or repairs need to be made to the radio telephone.

Radio telephone with compliant shield and method

An integrated dynamic amplitude limiter is disclosed for limiting the deviation of a transmitter operating at audio frequencies. In an amplitude limiter according to the invention, a dynamic AGC amplifier block (1), a level clipper block (3) and a block (2) which forms the higher and lower limiting levels are implemented using switched capacitors (SC), and they are formed into an integrated amplitude limiter circuitry, and the voltages which define the higher and lower limiting levels are formed from the voltage of the band-gap voltage reference (Vbgref), which voltage is formed in relation to the virtual ground voltage of the amplifier circuitry, in which case the limiting levels are independent of the supply voltage (Vdd).

Integrated dynamic amplitude limiter independent of the supply voltage

A circuit arrangement for a mobile telephone comprises a microprocessor responsive to a clock signal for controlling its functions, and a signalling circuit, e.g. a modem which is coupled to the microprocessor to provide an output clock signal thereto. In the idle states of the processor, the output clock signal is stopped, using a stop signal from the microprocessor. This gives use to reduce power consumption and a consequential increase in battery life.

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Oulu, Finland

Pertti J Korhonen