Koninklijke Philips Corporation N.v.

Telefonaktiebolaget Lm Ericsson (publ)

Philips Electronics North America Corporation

Petrus Martinus Stroet

Rishi Mohindra

Abolfazl Khosrowbeygi

A power mixer architecture for a transmitter chip is disclosed. The power mixer architecture is a mixing stage including one or more upper trees, and one or more lower trees. Each lower tree is selectively activated to receive current biasing signals, and current intermediate frequency signals. Upon receipt, the activated lower tree activates a corresponding upper tree to receive one or more amplified current intermediate frequency signals from the lower tree. In conjunction with a reception of voltage local oscillating signals, the upper tree provides voltage radio frequency signals. The gain of the lower tree is designed to be constant over any variance in a temperature, supply voltage or processing performance of the transmitter chip.

Power-mixer architecture for a transmitter

A received signal strength indicator operating at low intermediate of zero intermediate frequency is provided. The received signal strength indicator forms absolute values from an in-phase signal component and a quadrature signal component of a low or zero intermediate frequency signal that represents a received radio frequency signal. The absolute values are added. Logarithmic signal processing is performed either before absolute signal forming or after adding. Finally, low pass filtering is performed.

High dynamic range low ripple RSSI for zero-IF or low-IF receivers

A Time Division Multiple Access (TDMA) radio communication device is arranged for receiving radio signalling and information data in receive time slots. The radio communication device includes receiver circuitry for the filtering of received radio signals using a filter. The filter includes a tunable filter part and a tunable oscillator or resonator part, operatively connected such that control signals operative for the tuning of the oscillator part are also operative for the tuning of the filter part. A detector for the detection of the oscillator operation, a reference source and a comparator are arranged to provide the tuning control signals for the oscillator to operate in accordance with the reference source. The filter includes storage for storing the tuning control signals if said filter is made inoperative and for starting up the filter by using the stored tuning control signals.

TDMA master-slave filter tuning

A quadrature modulator with set-and-forget carrier leakage compensation. The quadrature modulator comprises an in-phase and a quadrature branch. In the in-phase and quadrature branches, real-time digital signals are converted to analog signals, the analog signals are filtered, and the filtered analog signals are modulated with a carrier signal and a ninety degrees phase shifted version of the carrier, respectively. The modulated in-phase and quadrature signals are added so as to form a quadrature amplitude modulated signal. Preferably upon powering up of the quadrature modulator, in the in-phase and quadrature branches, carrier leakage is measured. The measured carrier leakage is supplied to comparators, which toggle, when carrier leakage is minimal in the respective in-phase and quadrature branches. Upon powering up of the quadrature modulator, the state machine starts signal generators which inject compensation signals into the in-phase and quadrature branches, respectively, so that dc-offsets in the in-phase and quadrature branches are reduced, thereby reducing the carrier leakage in the in-phase and quadrature branches. When the comparators toggle, the state machine is commanded to stop controlling the corresponding signal generators of which output signals are then frozen.

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Sunnyvale, CA, United States of America

Petrus Martinus Stroet