Siemens Aktiengesellschaft

Gigaset Communications Gmbh

Volker Detering

Jurgen Lepping

Stefan Heinen

Dietmar Gapski

Georg Busch

Ralf Lorenz

Ludger Hinken

Jurgen Sauer

The invention relates to a printed board which comprises an inlay and on whose one face electrical components are provided and on whose other face at least one single cooling element for cooling the components is mounted. A component to be cooled, the inlay and the cooling element are aligned with each other. The components are SMD components of, e.g., a high-power output stage circuit with heat emissions of up to 10 to 15 watt. In order to cool the structure, the heat produced in a heating zone between the pins of a component to be cooled is guided to the inlay which is dimensioned in such a manner that it extends farther than below the pins of the component to be cooled. In order to prevent short-circuits and allow power connections, an additional layer is arranged on the printed board above the inlay and simultaneously below the component to be cooled and comprises thermic provisions between a component to be cooled and the inlay for ensuring a good to excellent heat conduction from the heating zone of a component to be cooled to the inlay.

Printed board

A transmit frequency is generated for a transceiver by a controllable oscillator which generates an oscillator frequency, a divider by a factor N, and a mixer stage with a subsequent band filter. Signals with the oscillator frequency and the oscillator frequency divided by the factor N are to the mixer stage to generate an output signal at the transmit frequency.

TDMA transmit frequency generator suppressing frequency jumps caused by feedback

In order to compensate changes in the resonant frequency of the resonator occurring owing to fluctuations in the distance between the reference distance (d ) and an actual distance (d &plusmn;&Dgr;d ) in an RF strip line resonator with a strip line ( ) which is arranged at a desired distance (d ) from a metallic conductor ( ), the strip line ( ) is curved. This curvature induces eddy currents in the conductor ( ). The eddy currents bring about a reduction in the inductance of the RF strip line resonator. The smaller/larger the distance between the strip line and the metallic conductor becomes, the smaller/larger this inductance becomes. Since shortening/lengthening the distance between the two conductors is however also accompanied by an increase/reduction in the capacitance of the RF strip line resonator, with the correct dimensioning of the curved strip line the two aforesaid effects cancel one another out and the frequency of the RF strip line resonator is approximately stable with respect to the given fluctuations in distance.

RF strip line resonator with a curvature dimensioned to inductively cancel capacitively caused displacements in resonant frequency

Antenna switch for wireless antenna diversity telecommunications devices

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Emmerich, Germany

Volker Detering