Abstract: Disclosed herein is a demodulator, including: a splitting/matching section for carrying out a matching process of making the amplitude and phase of a first modulated signal match respectively the amplitude and phase of a second modulated signal; and a demodulation section for generating a demodulated signal on the basis of the first modulated signal and the second modulated signal, which have been subjected to the matching process carried out by the splitting/matching section, wherein the splitting/matching section has a splitting section, a first matching section, and a second matching section, the first circuit-element constants determining the first input impedance of the first matching section and the second circuit-element constants determining the second input impedance of the second matching section are set at values determined in advance in order to make the first input impedance equal to the second input impedance.

Abstract: A semiconductor device is provided, which comprises a first demodulation circuit, a second demodulation circuit, a first bias circuit, a second bias circuit, a comparator, an analog buffer circuit, and a pulse detection circuit. An input portion of the pulse detection circuit is electrically connected to an output portion of the analog buffer circuit, a first output portion of the pulse detection circuit is electrically connected to an input portion of the first bias circuit, and a second output portion of the pulse detection circuit is electrically connected to an input portion of the second bias circuit.

Abstract: An RFID reader device (31), of the type comprising a demodulator (6) for receiving from a RFID tag (11) an AM (Amplitude Modulation) wave (20) having a predetermined frequency (f) and for retrieving, from the AM wave (20), a demodulated output (6a) associated to predetermined positive or negative Amplitudes of said AM wave (20), said demodulated output having a portion with a frequency F. The AM demodulation system comprises at least a second demodulator (26) for receiving the AM wave (20) and retrieving a second demodulated output (26a) associated to Amplitudes opposite to the predetermined positive or negative Amplitudes, said second demodulated output having a portion with said frequency F; the RFID reader includes a block (27) having, in input, the demodulated output (6a) and the second demodulated output (26a) and returning, in output, an enforced demodulated output (30) with a portion with frequency (f1) doubled with respect to said frequency (F).

Abstract: AM (Amplitude Modulation) demodulation system (36) for an RFID reader device (31), of the type comprising a demodulator (6) for receiving from a RFID tag (11) an AM (Amplitude Modulation) wave (20) having a predetermined frequency (f) and for retrieving, from the AM wave (20), a demodulated output (6a) associated to predetermined positive or negative Amplitudes of said AM wave (20). The AM demodulation system comprises at least a second demodulator (26) for receiving the AM wave (20) and retrieving a second demodulated output (26a) associated to Amplitudes opposite to the predetermined positive or negative Amplitudes and a block (27) having, in input, the demodulated output (6a) and the second demodulated output (26a) and returning, in output, an enforced demodulated output (30) with a frequency (f1) greater than the predetermined frequency (f).

Abstract: An envelope detector that does not generate an undesirable DC offset at its DC output signal. An envelope detector according to the present teachings includes a circuit for performing a DC level shift on an AC input signal applied to the envelope detector such that a magnitude of the DC level shift is proportional to a peak envelope of the AC input signal.

Abstract: A diode detector comprising a detector network adapted to detect and multiply the detected voltage coupled to a divider network that comprise diodes in equal number to the number of diodes in the detector network, provides a passive detector applicable to any application requiring a small, efficient, high output, inexpensive temperature compensated detector for use as demodulator or as power to voltage converter. Integrating a portion of the divider network in the detector/multiplier network allows control over the minimum input impedance of the detector.

Abstract: Two capacitors are provided for demodulating an amplitude-modulated signal and can be supplied with a signal that is rectified by a diode and that is at a voltage. The half-cycles of this signal are used for alternately charging the first or second capacitor using a switch. The capacitors are discharged using switches. Comparing the amplitude values, which are stored in the capacitors, of successive half-cycles in an evaluation unit allows simple and precise demodulation, which can be achieved with few components and can be carried out at very high frequencies.

Abstract: A diode detector comprising a detector network adapted to detect and multiply the detected voltage coupled to a divider network that comprise diodes in equal number to the number of diodes in the detector network, provides a passive detector applicable to any application requiring a small, efficient, high output, inexpensive temperature compensated detector for use as demodulator or as power to voltage converter.

Abstract: A detector comprises a first diode for detecting a high-frequency signal applied to the detector, a bias unit for supplying a predetermined bias voltage to the first diode; a first resistor having an end connected to the bias unit and another end connected to the first diode, a second diode connected in series with the first diode and having a same characteristic as the first diode, a second resistor having an end connected to the second diode and another end connected to a ground, and a detected voltage output terminal directly connected to a junction between the first diode and the second diode. The sum of a detected voltage generated by the first diode and a DC offset voltage caused by the bias voltage appears at the detected voltage output terminal. The first resistor has a resistance value different from that of the second resistor, and those resistance values are set to compensate for variations in the detected voltage with temperature.

Abstract: A contactless chip card, receiving binary data transmitted by radio frequency, includes a demodulator for the binary data. The demodulator includes a circuit for the detection of the transmitted signals, a rectifier circuit, a bandpass filter, two comparators and a memory circuit. The bandpass filter provides a low-frequency signal used as a reference for the two comparators and a high-frequency signal that is compared with the references varying with the low frequency signal. As a result, the demodulation is independent of the mean level of the received signal.

Abstract: An I/Q-modulator or I/Q demodulator circuit in which the modulating signals (2, 3) are input through the output phase transfer branches of the circuit. In relation to the RF-characteristics, a series resistor (16) and a series inductance (20) in the phase transfer circuits are grounded with small capacitors (23, 25). A capacitor (17) having a high impedance at the modulating frequency is located between the branches. Tho modulating signals are not summed through the capacitor (17), and, thus, their phase difference is not weakened.

Abstract: A wide power range radiation monitor includes a pair of diodes with their cathodes interconnected and with an additional capacitor coupled in parallel to one of the diodes. The detector, of the radiation monitor provides two outputs, a low power output and a high power output, which outputs are connected to the anodes of the detector diodes. The arrangement of dual diodes and capacitance provide the diode detector of the monitor with a greater than 40 dB square law region.