Abstract: A testing method or apparatus utilizes multiple frequencies applied to a device under test for measuring newly discovered frequency modulation effects. An embodiment may include a lower frequency signal with a smaller amplitude higher frequency signal to test a dynamic change in frequency response, gain, and or phase. This dynamic test can reveal frequency modulation effects. Another embodiment may include the use of a multiple frequency signal to dynamically induce a time varying phase or frequency distortion for the device that has differential phase distortion. The device's output is then measured with an FM detector to measure a shift in one of the frequencies used in the test signal or to measure frequency modulation effects of any signals, including distortion products, from the device.

Abstract: A method and a device are described for testing a frequency-modulated clock generator, the device including a cycle counting unit for counting clock cycles of a clock signal of the clock generator in multiple consecutive measuring periods, which are defined, in particular, by a measuring signal having a measuring frequency, and for outputting cycle count values, and including a comparator device for receiving and comparing the cycle count values with each other and for outputting at least one output signal as a function of the comparison. In particular, ascertained maximum and minimum values may be compared with each other.

Abstract: The dimming circuit includes a reference signal generation unit, a frequency modulation unit and a duty cycle control unit. The reference signal generation unit generates a reference signal. The frequency modulation unit generates a frequency modulation signal having an initial frequency based on the reference signal and a control signal, repeatedly performs a counting operation that counts at least one pulse of the frequency modulation signal, and adjusts the frequency of the frequency modulation signal if the counting operation is completed. The duty cycle control unit generates a pulse width modulation (PWM) output signal by adjusting a duty cycle of the frequency modulation signal.

Abstract: A testing method or apparatus utilizes multiple frequencies applied to a device under test for measuring newly discovered frequency modulation effects. An embodiment may include a lower frequency signal with a smaller amplitude higher frequency signal to test a dynamic change in frequency response, gain, and or phase. This dynamic test can reveal frequency modulation effects. Another embodiment may include the use of a multiple frequency signal to dynamically induce a time varying phase or frequency distortion for the device that has differential phase distortion. The device's output is then measured with an FM detector to measure a shift in one of the frequencies used in the test signal or to measure frequency modulation effects of any signals, including distortion products, from the device.

Abstract: The invention relates to a transmission module for transmitting data in the form of useful digital signals by modulation of a carrier, determined by the useful signals, by means of frequency shift keying. The transmission module contains a PLL circuit with a voltage-controlled oscillator and a controllable frequency divider with a frequency divider control input. The transmission module is designed to induce direct frequency shift keying (DFSK) of the carrier signal by appropriate triggering of the frequency divider with at least two different frequency divider control signals, and it has a modulation data preprocessing unit, which is connected to the frequency divider control input and is designed to weight samples of the same polarity of the useful signals to be transmitted and to fine tune the frequency divider control signal with regard to the frequency deviation to be induced.

Abstract: Circuitry and methods are provided. Voltage and current of an electrical load are detected, scaled and biased to derive respective voltage and current signals. Frequency-modulated signals corresponding to the voltage and current signals are respectively derived. The frequency-modulated signals are communicated between different electrical domains by way of optical isolation barriers. The frequency-modulated signals are processed to improve linearity and to time-correlate the signals to discrete samplings of the load voltage and current. Control of a printer or other device is performed using the processed signals.

Abstract: A system and method for providing, among other things, wideband phase modulation is described. Several embodiments include a scaling network for scaling an input modulation signal in accordance with a scaling parameter and thereby generating a scaled modulation signal that is applied to a voltage-controlled oscillator of a phase-locked loop. A sensing network may also be included for detecting changes in one or more parameters characterizing the voltage-controlled oscillator. A calibration adjustment network may additionally be included for adjusting the scaling parameter in accordance with the changes in the one or more parameters.

Abstract: Circuitry and methods are provided. Voltage and current of an electrical load are scaled, biased and alternately sampled to derive a multiplexed signal. The multiplexed signal is used to control an oscillator so as to provide a multiplexed frequency-modulated signal. The multiplexed frequency-modulated signal is processed to improve linearity and to time-correlate signal content with discrete samplings of the load voltage and current. Control of a printer or other device is performed using the processed signal.

Abstract: A frequency modulator includes a tuning circuit configured to determine a nominal gain characteristic of a digitally controlled oscillator (DCO) in a first mode, and to determine an actual gain characteristic of the DCO in a second mode using the nominal gain characteristic. The frequency modulator also comprises a modulation circuit comprising the DCO coupled to the tuning circuit, configured to modulate a frequency of a DCO output signal with a modulation signal input, and to scale the modulated DCO output signal based on the actual gain characteristic in the second mode to provide gain compensation and frequency modulation of the DCO. The tuning circuit may include a select switch to couple a minimal and maximal tuning word to the DCO in the first mode and an actual operating point word in the second mode to the DCO to determine the nominal gain characteristic.

Abstract: A mixer circuit accumulates I signal (digital signal of first channel) having its band limited by low-pass filter and first carrier signal to perform two-phase shift keying modulation thereon. An adder adds fundamental-wave component of bit clock signal BCK into Q signal (digital signal of second channel) having its band limited by the another low-pass filter to obtain a resultant added-up signal. Another mixer circuit accumulates the added-up signal and second carrier signal to perform two-phase shift keying modulation thereon. Output signals of the mixer circuits are input to another adder so that they may be added up to obtain a QPSK signal as a modulated quadrature signal. The QPSK signal contains frequency signals whose frequencies are a sum of bit clock frequency and carrier frequency and a difference between them. When demodulating, the carrier signal and the bit clock signal are reproduced using the frequency signals.

Abstract: A modulation-signal generating circuit includes a temperature monitoring unit that detects a casing temperature of the circuit, a voltage control oscillator including two variable impedance circuits that independently control oscillation frequency based on an input control voltage, a frequency-correction-voltage generating unit that outputs a voltage for compensating for a temperature drift of an oscillation frequency according to the casing temperature detected by the temperature monitoring unit, to one of the variable impedance circuits, and an FM-modulation-voltage generating unit that outputs a modulation voltage containing a constant DC component not depending on temperature and a predetermined AC component, to the other variable impedance circuit, under a temperature drift compensation condition of the frequency-correction-voltage generating unit.

Abstract: A testing method or apparatus utilizes multiple frequencies applied to a device under test for measuring newly discovered frequency modulation effects. An embodiment may include a lower frequency signal with a smaller amplitude higher frequency signal to test a dynamic change in frequency response, gain, and or phase. This dynamic test can reveal frequency modulation effects. Another embodiment may include the use of a multiple frequency signal to dynamically induce a time varying phase or frequency distortion for the device that has differential phase distortion. The device's output is then measured with an FM detector to measure a shift in one of the frequencies used in the test signal or to measure frequency modulation effects of any signals, including distortion products, from the device.

Abstract: Embodiments of the invention describe a method and a device for digital measurement of the momentary frequency response of the phase-path component of a modulator, based on digitally sampling the output frequency of the modulator by clocks and count values derived from components already used by the modulator, e.g. a counter in a divider, and a reference frequency based on a crystal oscillator.

Abstract: A method (for example, machine-implemented, e.g., via a receiver), for determining whether a transmitted pulsed-signal is a linear or non-linear frequency modulated (FM) signal, includes: iteratively determining upper and lower bound slopes associated with frequency components of a pulse of a signal during a time period of the pulse; and comparing each determined upper bound slope to a previous or initial upper bound reference slope and comparing each determined lower bound slope to a previous or initial lower bound reference slope in order to determine the linearity, or non-linearity, of the signal.

Abstract: An electromagnetic resonant sensor has a dielectric sensor body through which electromagnetic wave energy is propagated. The sensor body has a cavity, with surfaces facing one another to define a gap that varies as a function of a parameter to be measured. The resonant frequency of an electromagnetic standing wave in the body and the variable gap changes as a function of the gap dimension.

Abstract: A free loop oscillator system including a set of successive delay elements connected in series forming a free-running loop oscillator, a set of taps disposed between the delay elements, a circuit for determining the speed of the free-running loop oscillator, and circuit for choosing a given tap in response to the speed of the free-running loop oscillator. Such a system may be implemented as a part of interval timer, a printer controller, a frequency synthesizer, an FM modulator, a digital-to-analog converter, or any other device which requires the availability of finely addressable signals since the taps disposed between the delay elements present signals much finer than any presently available clock.

Abstract: A circuit is disclosed for detecting RF pulses, regardless of the frequens associated therewith. Such pulses are characterized by envelope configurations of a common frequency and perceived with a frequency analyzer that responds to that common frequency. In the preferred embodiments, a static Chirp-Z analyzer is incorporated when narrow pulses are of primary interest and a dynamic Chirp-Z analyzer is incorporated when wide pulses are of primary interest. In other embodiments, static transform gain is enhanced with dynamic transform gain.

Abstract: An electrical circuit comprising means for receiving an input signal for encoding or modulating and amplification. Multiple amplification stages including at least one transconductance amplifier are provided. There are means for having the input signal modulate the oscillator constituted by the multiple amplification stages to provide a 360.degree. phase-shifted signal at a predetermined frequency. Gain control means are also provided for developing level for permitting oscillation under conditions including at least the conditions of turn on of the circuit and other operating conditions. The gain control means includes a transistor and resistor network for adjusting the gain to sustain the oscillation. The transistor and resistor also regulate amplification of an intermediate stage of the amplifier. The preamplifier directly converts an EKG and/or other signals to linearized control currents which modulate the oscillator.

Abstract: A system and method for encoding and decoding a frequency-shift keyed data signal for transmission over a non-ideal communications channel that utilizes phase-coherently combined halfwave segments of sinewaves with a finite number of different frequencies and equal amplitudes. A stream of data characters is encoded into a transmit sequence {S(n)} of positive numbers which defines an ac signal of halfwave segments of sinewaves of fixed, preselected amplitude. The ac signal encoding the stream of data characters is transmitted over the communications channel and received as a perturbed ac signal. The received signal is identified by consecutively determining the time durations between peak values or between zero crossings of each segment yielding a receive sequence {E(n)} of positive numbers. All or parts of this receive sequence are then compared with each of a set of preselected, stored sequences, each representing a stream of none, one or more data characters.