Em Microelectronic-marin Sa

Marvell International Limited

Michel Moser

David Cousinard

Cao-Thong Tu

Alessandro Venca

An RFID circuit and to a demodulator for an RFID circuit, the demodulator including an input and at least one output, a clock extractor connected to the input, a comparator connected to at least one output, a finite impulse response FIR filter arrangement connected to the input and connected to the comparator.

Demodulator for an RFID circuit

The circuit is provided for the transmission of data amplitude modulated radio frequency signals. The circuit includes a local oscillator for generating an oscillating signal at a determined carrier frequency, a unit for shaping data pulses to supply a data amplitude modulation control signal (Vmod), and a power amplifier receiving the oscillating signal and the data amplitude modulation control signal (Vmod) for the transmission of data amplitude modulated radio frequency signals by an antenna or an antenna arrangement. The data pulse shaping unit () includes a pulse shaper () for digitally adapting the data transition edges on the basis of an incoming digital data signal (d), and a digital-analog conversion stage () for converting a digital data signal shaped in the unit, in order to supply the data amplitude modulation control signal (Vmod) to the power amplifier.

Circuit for transmitting ASK RF signals with data signal edge adaptation

In one embodiment, the present invention includes noise reduction circuits and methods. In one embodiment, cross coupled switching transistors incorporate bias voltages between the control terminal of each transistor and the drain of the other transistor. The bias voltages increase the voltage on each transistors drain terminal and reduce noise upconversion in the system. In one embodiment, the source voltages of each transistor may be increased to linearize the circuit and further reduce noise. In another embodiment, a current is coupled to a PN junction to generate a low noise bias voltage. The bias voltage is used to bias capacitors of a selectively activated and deactivated capacitance to reduce noise. Features and advantages of the present invention may be implemented in an oscillator circuit, which may be used in a communication system, for example.

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Cheyres, Switzerland

Michel Moser