Telefonaktiebolaget Lm Ericsson (publ)

St-ericsson Sa

Ericsson Modems Sa

Janne Peltonen

Christian Elgaard

Anna-Karin Stenman

Sami Vilhonen

Kimmo Koli

Mika Salmi

Antti Rauhala

Anna Karin Stenman

A switched mode power supply comprises a control signal generator arranged to generate first and second control signals via first and second outputs, respectively, which are coupled to respective first and second inputs of a switching stage, by means of respective first and second control signal paths. The switching stage is arranged to, responsive to the first and second control signals, alternately charge and discharge the reactive element by coupling it alternately to first and second supply voltages. An adjustable delay stage in one of the first and second signal paths is arranged to control an adjustable delay so that a first delay experienced by the first control signal passing from the control signal generator's first output to the switching stage's first input is substantially equal to a second delay experienced by the second control signal passing from the control signal generator's second output to the switching stage's second input.

Switched mode power supply

An oscillator circuit comprises a crystal oscillator arranged to generate an oscillation signal, a bias current generator arranged to supply a bias current to the crystal oscillator, and a feedback stage arranged to generate a feedback signal in response to an amplitude of the oscillation signal reaching an amplitude threshold. The bias current generator is arranged to: in response to a supply of power to the oscillator circuit being switched on, generate the bias current at an increasing level commencing from a first level; in response to the feedback signal, terminate the increasing; and during subsequent oscillation of the crystal oscillator, supply the bias current at a second level dependent on a final level of the bias current reached when the increasing is terminated.

Oscillator circuit with bias current generator

An oscillator circuit () comprises a crystal oscillator () arranged to generate an oscillation signal, a bias current generator () arranged to supply a bias current to the crystal oscillator (), and a feedback stage () arranged to generate a feedback signal in response to an amplitude of the oscillation signal reaching an amplitude threshold. The bias current generator () is arranged to: in response to a supply of power to the oscillator circuit () being switched on, generate the bias current at an increasing level commencing from a first level; in response to the feedback signal, terminate the increasing; and during subsequent oscillation of the crystal oscillator (), supply the bias current at a second level dependent on a final level of the bias current reached when the increasing is terminated.

A switched mode power supply () comprises a reactive element () and a control signal generator () is arranged to generate a first control signal at a first output () of the control signal generator () and a second control signal at a second output () of the control signal generator (). The first output () of the control signal generator () is coupled to a first input () of a switching stage () by means of a first control signal path () and the second output () of the control signal generator () is coupled to a second input () of the switching stage () by means of a second control signal path (). The switching stage () is arranged to, responsive to the first and second control signals, alternately charge and discharge the reactive element () by coupling it alternately to first and second supply voltages. A delay detector () is arranged to generate a delay indicator signal indicative of a relative delay between the first control signal at the first input () of the switching stage () and the second control signal at the second input () of the switching stage (). An adjustable delay stage () in one of the first and second signal paths () is arranged to, responsive to the delay indicator signal, control an adjustable delay so that a first delay experienced by the first control signal passing from the first output () of the control signal generator () to the first input () of the switching stage () is substantially equal to a second delay experienced by the second control signal passing from the second output () of the control signal generator () to the second input () of the switching stage ().

The invention provides circuitry integrated into a silicon chip that measures aspects of an RF signal on a transmission line in order to provide data that is ultimately used by an antenna tuner circuit to substantially match the impedance of the antenna with that of the transmission line providing the RF frequency to be transmitted.

Standing wave ratio meter for integrated antenna tuner

A system () comprises a first circuit () for transmitting information to a second circuit (). The first circuit () comprises a signal generator () arranged to generate a signal () for transmission to the second circuit (). The signal () has a first state for causing the second circuit () to perform a first operation and a second state for causing the second circuit () to perform a second operation. The signal generator () comprises means to modulate the generated signal () during a data burst period () to encode data into the generated signal (). The data burst period () occurs within a period in which the generated signal () is in the second state. The signal () is modulated such that the encoded data is distinguishable from the generated signal (). In an embodiment, a data burst period () comprises a plurality of data periods () during which the state of the signal is representative of the data encoded in the signal (). The data periods () may be separated by padding periods () during which the signal () is in the second state, The data burst period may be initiated following a delay after the signal changes from being in the first state to being in the second state.

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Salo, Finland

Janne Peltonen