Nokia Corporation

Nokia Mobile Phones Limited

Karl-Erik Gustafsson

Jarmo J Heinonen

Jyrki Koljonen

Jussi Salminen

Nina Muurinen

Tapio Mantysalo

Jarmo Heinonen

The invention relates to an enhanced shielding arrangement. A shielding arrangement comprises a shielding can and a layered printed circuit board having electrical components and at least two ground potential layers. There are grounding connections between edges of the shielding can and at least one of the ground potential layers, and grounding connections between components inside the shielding can and at least one of the ground potential layers, so that the two grounding connections are connected to each other only through at least one of the ground potential layers for providing small loops.

Shielding arrangement

A microphone structure comprising a microphone (M) and an electro-static discharge protector (ZD) placed close to microphone capsule (), preferably inside it. Further the structure comprises within the microphone capsule an e.g. ladder-type filter having parallel capacitors (C, C, C) and series resistors or coils (R, Z) protecting the microphone from radio frequency disturbances. Structure parts may be on same circuit board or in same integrated circuit (IC). Structure is less susceptible to RF disturbances than known structures and its production costs are lower.

Microphone structure

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Turku, Finland

Karl-Erik Gustafsson