Telefonaktiebolaget Lm Ericsson (publ)

Walter Kodim

Herbert Dingfelder

Harald Thomas

Roman Gloeckler

Frank B&auml;uerlein

An R.F. power amplifier circuit comprising a power control loop is described. The power control loop includes an R.F. power amplifier having a power control input and a power supply input as well as at least one feedback path coupled between the power control input and the power supply input of the power amplifier. The feedback path includes at least one variable loop element that has a control terminal configured to reduce variations of control loop parameters.

R.F. output power control

To maintain a receiving sub-system in a multiple standard communication device fully operational according to all operation modes of a second transmitting sub-system of the multiple communication device it is proposed that a multiple standard communication device of the type with parallel operation comprises a first subunit at least receiving input signals at a predetermined input level, and a second subunit at least transmitting output signals at a specific time, frequency and output level such that the output level is very large compared to the input level of the first subunit. According to the present invention the operation mode of the first subunit is modified when the second subunit is transmitting output signals.

Parallel operation of devices using multiple communication standards

A multiband transformation stage () comprising a common first signal port (), a common second signal port () and a signal path () coupled between the first signal port () and the second signal port () is described. The signal path () is switchable between a first state with a first quarter-wavelength transformer characteristic for a first frequency band, a second state with a second quarter-wavelength transformer characteristic for a second frequency band and a third state with a transmission characteristic. The invention also relates to a multiband switching device comprising the multiband transformation stage () in combination with a low-power switching stage ().

Multiband R. F. switching device

An R.F. antenna switch ( ) for coupling either a high-loss port ( ) or a low-loss port ( ) to a common port ( ) includes an unequal power splitter ( ) with the high-loss port ( ), the low-loss port ( ), and the common port ( ). The unequal power splitter ( ) further has at least one high-loss path ( ) coupled between the common port ( ) and the high-loss port ( ) and a low-loss path ( ) coupled between the common port ( ) and the low-loss port ( ). The R.F. antenna switch ( ) further comprises a switching element ( ) having an input ( A) coupled to the low-loss port ( ) and an output ( B) coupled to a terminating element ( ). The low-loss port ( ) is terminated with the characteristic impedance of the unequal power splitter ( ) when the switching element ( ) is switched on.

R.F. antenna switch for use with internal and external antennas

The invention relates to a device and a method for temperature compensation via the determination of cut-angles of a master and a slave crystal (mc, sc) employed in a master and slave oscillator (m, s). When the master and the slave oscillator (m, s) have been tuned to their center frequencies (fc_m, fc_s), then the temperature characteristic of the slave oscillator (s) is actively detuned with respect to the temperature characteristic of the master oscillator (m). In a detuned state a frequency ratio parameter (n_s) of the slave to the master output frequency (f_s/f_m) is determined and the cut-angle is determined by using this parameter (n_s) to read out the cut-angle dependent on the temperature (T) from a memory (MEM). The invention also relates to a temperature compensation device and method where two crystals of different cut-angles are used and a frequency ratio parameter is determined to determine the identity/symmetry or difference of the cut-angles. Particular useful applications of the invention are in dual-mode mobile telephones which require the use of at least two oscillators with different resonant frequencies.

Matched crystal temperature compensation device

The invention compensates for any interference from a mobile communication unit to a positioning receiver unit in a multiple standard communication device with mobile communication and localization functionality. A first sub-unit receives input signals at a predetermined input level. A second sub-unit transmits output signals at an output level that is large compared to the input level of the first sub-unit. A branch-off unit branches off a part of the output signal before the antenna of the second sub-unit. An interference suppression unit receives the branch-off part of the output signal and derives an interference compensation signal therefrom through attenuation and subsequent phase shifting. The interference compensation signal is supplied to a superposition unit that also receives the input signal of the first sub-unit.

RECEPTION OF WEAK RADIO FREQUENCY SIGNAL IN THE PRESENCE OF A STRONG INTERNAL RADIO FREQUENCY INTERFERER&mdash;DEVICE AND METHOD FOR COMPENSATION OF AN INTERNAL INTERFERING SIGNAL BY A SUPERPOSITION METHOD

The invention relates to an electrical component (CO) as well as a device (DEV) comprising such an electrical component (CO) and an electric circuit module (MO). A ground plane (,) of the component (CO) and a ground plane (,) of the circuit module (MO) are brought into contact via projections (,&Prime;) provided on the ground plane (,) of the component (CO) and/or on the ground plane of the circuit module (MO). The provision of the projections (,&Prime;) and the recesses (,&prime;) therebetween provide heat sinks between the projections (,&Prime;) when they are soldered to the ground plane (,) of the circuit module (MO). Through-holes (,&prime;) and additional non-ground conductors (,&prime;) can be provided between pads (,) of the ground plane (,) of the circuit module (MO) allowing an efficient use of the available space. The invention is particularly useful when a patch antenna needing a large ground plane is connected to a multilayer circuit board. Another embodiment of the invention comprises a plurality of spacer elements which are arranged between the ground planes (,) of the circuit module (MO) and of the component (CO), such that the ground planes (,) can be kept flat. This allows a design of the configuration of the ground plane of the circuit module (MO) independently from a configuration of the component (CO).

Electrical component and an electrical circuit module having connected ground planes

For controlling a position indicator, e.g. a cursor, on a visual display, e.g. the monitor screen associated with a personal computer or a laptop computer screen, a position indicator controlling device (1) comprises an indicator position controller (6) in the form of a continuous membrane of elastomeric material (8) stretched, in wrinkle-free manner, around a solid form-keeping core (7) held captive in a housing (2) so that by applying finger pressure in a generally horizontal direction to an uppermost exposed, part-spheroidal, portion of the membrane, the membrane can slide on the core to produce a corresponding output signal from one or more motion detectors (11, 12). The indicator position controller gives the appearance to a user of a spherical ball device (such as is commonly used in a laptop computer), but the special shape of the form-keeping core is such as to reduce the overall height requirement and leads to a heightwise compact construction for the position indicator controlling device (1'). According to two modifications (FIGS. 5 and 6), the indicator position controller (6) is realized by a normally spheroidal thick-walled elastomeric ball (8'), or by a solid elastomeric ball (8') held in a deformed state by the housing (2). The position indicator controlling device (1) can be designed for use as a ball-type device for a laptop computer or as a mouse for a personal computer.

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Nürnberg, Germany

Walter Kodim