Abstract: A capacitive sensor includes a switching capacitor circuit, a comparator, and a charge dissipation circuit. The switching capacitor circuit reciprocally couples a sensing capacitor in series with a modulation capacitor during a first switching phase and discharges the sensing capacitor during a second switching phase. The comparator is coupled to compare a voltage potential on the modulation capacitor to a reference and to generate a modulation signal in response. The charge dissipation circuit is coupled to the modulation capacitor to selectively discharge the modulation capacitor in response to the modulation signal.

Abstract: Systems and methods for generating pulsed output signals that employ a gated RF oscillator circuit having an output that is switchably grounded through the emitter of a transistor and including feedback from the output of the circuit to the base of the transistor to create oscillations and to allow a digital input pulse of a desired length to control the start and stop of oscillations created by the transistor.

Abstract: Exemplary gate pulse modulation circuit and sloping modulation method applied thereto are provided. The gate pulse modulation circuit has an output terminal and includes a voltage modulation circuit and a comparator control circuit. The voltage modulation circuit is electrically coupled between a gate power supply voltage and a second voltage and subjected to the control of a sloping control signal to perform a sloping operation and then output a sloped voltage signal. The comparator control circuit includes a comparing unit and a switching unit. First and second input terminals of the comparing unit respectively are electrically coupled to a node and a first voltage. During the voltage modulation circuit performing the sloping operation, a magnitude relationship between a voltage on the node and the first voltage decides on-off states of the switching unit and thereby decides the moment of the first voltage delivered to the output terminal.

Abstract: Exemplary gate pulse modulation circuit and sloping modulation method applied thereto are provided. The gate pulse modulation circuit has an output terminal and includes a voltage modulation circuit and a comparator control circuit. The voltage modulation circuit is electrically coupled between a gate power supply voltage and a second voltage and subjected to the control of a sloping control signal to perform a sloping operation and then output a sloped voltage signal. The comparator control circuit includes a comparing unit and a switching unit. First and second input terminals of the comparing unit respectively are electrically coupled to a node and a first voltage. During the voltage modulation circuit performing the sloping operation, a magnitude relationship between a voltage on the node and the first voltage decides on-off states of the switching unit and thereby decides the moment of the first voltage delivered to the output terminal.

Abstract: It is an object of the invention to provide a pulse generation circuit and a modulator for realizing a high On/Off ratio in a small circuit scale and with lower power consumption. A short pulse generation circuit according to the invention includes an oscillator 101, a control signal generation circuit 102, an intermittent frequency multiplier 103, a filter 104, and an output terminal 105. The oscillator 101 and the intermittent frequency multiplier 103 are active circuits implemented as active elements. A continuous signal is output from the oscillator 101 and is input to the intermittent frequency multiplier 103 and the intermittent frequency multiplier 103 intermittently operates according to a control signal output from the control signal generation circuit 102, thereby generating a short pulse signal, and a spurious component is removed through the filter.

Abstract: An electronic component includes an RFID transponder, and also a security document comprises such an electronic component. The electronic component has a modulator for modulating a carrier signal, the modulator being constructed from at least two organic field effect transistors.

Abstract: A radio frequency modulator system having a radio frequency amplifier controlled by a pulse modulator. The pulse modulator includes: a first switching circuit response to an input pulse for coupling a dc voltage relative to a reference potential to the output electrode when the radio frequency signal is to be amplified by the radio frequency amplifier and for decoupling the dc voltage from the output electrode when the radio frequency signal is to be decoupled from the output electrode wherein charge is stored in the storage element when the dc voltage is coupled to the output electrode; and: a second switching circuit responsive to the input pulse for discharging the stored charge when the dc voltage is decoupled from the output electrode.

Abstract: In a contactless IC card system, a modulating circuit manufactured in an IC form is operable at a high power efficiency. The demodulating apparatus is configured to include: first signal output means for outputting a first output signal having a predetermined phase with respect to that of an input signal, a second signal output means for outputting a second output signal having a predetermined phase with respect to that of the input signal, gate means for gating at least the second output signal, calculation means for adding, or subtracting the first output signal and the second output signal; and control means for controlling the operation of the gate means in response to a logic level of input data.

Abstract: In a contactless IC card system, a modulating circuit manufactured in an IC form is operable at a high power efficiency. The demodulating apparatus is configured to include: first signal output means for outputting a first output signal having a predetermined phase with respect to that of an input signal, a second signal output means for outputting a second output signal having a predetermined phase with respect to that of the input signal, gate means for gating at least the second output signal, calculation means for adding, or subtracting the first output signal and the second output signal; and control means for controlling the operation of the gate means in response to a logic level of input data.

Abstract: A method is performed for influencing the signal shape of an output signal of an RF power resonance amplifier and an RF excitation arrangement including an RF power resonance amplifier. A basic signal of a basic frequency is amplified and modulated with a modulation signal, and an output oscillating circuit of the RF power resonance amplifier is tuned to a frequency in the range of the basic frequency, and is excited with the basic signal during normal operation. At times that are or can be predetermined, the output oscillating circuit is driven with a driving signal that differs from the basic signal, for a time period that is or can be predetermined. This reduces the dying down time of the output oscillating circuit and increases the steepness of the output signal edges.

Abstract: Direct up-conversion of a signal is accomplished using a sampling pulse generator circuit and a gated differential amplifier, enabled by the sampling signal. When not enabled, the output of the differential amplifier is pulled to zero. The sampling pulse is generated from a base frequency sine wave which is squared with a limiting amplifier, and further passed through one or more frequency doublers producing a times two signal, a times four signal and so on. The squared base frequency and frequency doubled signals are logically ORed to produce a short duration pulse which repeats at the frequency of the base signal. The resulting output is an amplitude modulated pulse doublet time domain waveform.

Abstract: An ASK modulator can be operated with only a positive-voltage power source. A source-voltage switching circuit that applies a positive voltage to the source of a FET when a data signal is at an L level in relation to the source of the FET is connected to the source of the FET which has a negative pinch-off voltage. Since the L level of the data signal can be set to 0 V, the ASK modulator can be configured only with the positive-voltage power source. This allows miniaturization and cost reduction to be implemented.

Abstract: In a contactless IC card system, a modulating circuit manufactured in an IC form is operable at a high power efficiency. The demodulating apparatus is configured to include first signal output means for outputting a first output signal having a predetermined phase with respect to that of an input signal, a second signal output means for outputting a second output signal having a predetermined phase with respect to that of the input signal, gate means for gating at least the second output signal, calculation means for adding, or subtracting the first output signal and the second output signal; and control means for controlling the operation of the gate means in response to a logic level of input data.

Abstract: A Pulse Amplitude Modulation (PAM) generator that generates multilevel PAM signals at frequencies over 1 GHz is disclosed. The PAM generator uses Emitter Coupled Logic (ECL) technology that implements differential pair current switches such that the outputs are summed to produce precisely balanced PAM signals.

Abstract: An amplitude-shift-keyed (ASK) optical transmitter is described for generating an ASK modulated infrared signal from a light-emitting-diode (LED). The transmitter includes a DC powered microcircuit for generating an ASK modulation signal. A pair of mosfet devices are connected in series with one or more LED's between the mosfets. An oscillator signal used to operate the microcircuit is also employed as a carrier signal to activate one mosfet while the ASK modulating signal is coupled to operate the other mosfet. Input capacitances of the mosfets are used to tune the oscillator signal and smooth the leading and trailing edges of the ASK modulation signal. Several embodiments are described.

Abstract: An analog direct current to one MHz information channel is provided, with high acccuracy and 10K volt input-output isolation. The information channel has a voltage to current converter which receives the analog input signal, and whose output is modulated by a square wave generator and provided to a center tap of the primary winding of a transformer. On the output side, the secondary winding of the transformer provides the signal to a precision rectifier which recovers the analog input signal.