Infineon Technologies Ag

Xiaopin Zhang

Stefan Herzinger

Michael Asam

Gunther Kraut

Martin Simon

Helmut Herrmann

A polar loop transmission circuit is proposed wherein a signal to be transmitted and a feedback signal are separated into their polar phase and amplitude components and the components are compared to one another for realizing a phase and amplitude modulation. An amplitude modulator controlled by an amplitude modulation signal is provided, whereby the amplitude modulator follows an oscillator and is preferably fashioned as a nonlinear amplifier that is operated in saturation. An amplifier attenuating the output signal of the amplitude modulator is provided in the feedback path. The present transmission architecture is suitable for future mobile radio telephone systems having a phase and amplitude modulation and are based on the known GSM standard, for example.

Polar loop transmission circuit

A controllable current source circuit and a phase locked loop contained such a circuit are disclosed. The current source circuit such a single switched driver stage for a switched actuation of the loop filter. A continuously switched-on driver stage is introduced into one of several paths of the current source circuit, so that a continuously weaker current is drawn by the loop filter. The currents are preferably stabilized via a current mirror circuit.

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Munich, Germany

Xiaopin Zhang