Abstract: Systems, devices, and methods related to phase shifters are provided. An example apparatus includes a first node to receive an input signal, a second node, a first signal path coupled between the first node and the second node, and a second signal path coupled between the first node and the second node. The first signal path includes a positively coupled transformer. The second signal path includes a negatively coupled transformer. The second signal path is out-of-phase with the first signal path at the second node. The apparatus further includes a plurality of switches to select the first signal path or the second signal path. The apparatus may further include tuning capacitors to improve phase-shifting performance of the apparatus.

Abstract: A cascaded radar system is provided that includes a master radar system-on-a-chip (SOC) with transmission signal generation circuitry and a slave radar SOC coupled to an output of the master radar SOC to receive a signal from the transmission signal generation circuitry of the master SOC. In this system, the slave radar SOC is operable to measure phase noise in the signal received from the transmission signal generation circuitry of the master SOC.

Abstract: Apparatus and methods for determining an inertia characteristic of a synchronous area of an electric power grid are described. First data is determined. The first data represents a signal comprising a first variation in the grid frequency over a period of time, the signal resulting from a second variation, the second variation being a variation in provision of electric power to and/or consumption of electric power from the grid, the signal having been filtered according to a first filter defining a first frequency band to at least attenuate frequencies outside of the first frequency band. Second data is determined. The second data is representative of the second variation on a second frequency band, the second frequency band being substantially the same as the first frequency band. An inertia characteristic of a synchronous area of the electric power grid is determined based on the first data and the second data.

Abstract: A radio access node comprises four logical antenna ports respectively mapped to four physical antennas. Responsive to a loss of data transmission from one of the four physical antennas, the radio access node transmits reference signals representing the four logical antenna ports on the remaining three physical antennas. Each reference signal represents a respective antenna port of the four logical antenna ports. The radio access node also scales transmission power of a physical antenna transmitting more than one of the reference signals based on the number of the reference signals the physical antenna transmits.

Abstract: A measurement circuit for measuring at least one of the rotational position and rotational speed of the rotor of an electric motor, typically such as may be used in an electric power assisted steering apparatus, the circuit comprising: first and second inputs for receiving first and second input signals which vary cyclically with the rotational position of the rotor, the first and second input signals at the first and second inputs varying in quadrature with each other; a phase detector circuit; and an observer circuit; in which the observer circuit is arranged to generate estimates indicative of the frequency and phase of the first and second input signals; in which the phase detector circuit is arranged to determine the phase difference between first and second estimated signals varying cyclically and at the frequency indicated by the estimates with a phase difference dependent on the phase difference indicated by the estimates, the first and second estimated signals varying in quadrature with each other on

Abstract: A receiver having Inphase-Quadrature (I-Q) imbalance compensation and an I-Q imbalance compensation method are provided. The receiver calculates a cross-ratio parameter according to a first ideal receiving value and a first ideal conjugate receiving mirror of a first receiving signal and a second ideal receiving value and a second ideal conjugate receiving mirror of a second receiving signal. The receiver calculates an I-Q imbalance compensation parameter according to the cross-ratio parameter, the first ideal receiving value, the first ideal conjugate receiving mirror, the second ideal receiving value, the second ideal conjugate receiving mirror, the first receiving signal and the second receiving signal. The receiver compensates a third receiving signal according to the I-Q imbalance compensation parameter.

Abstract: A railway positioning system provides an on-board speed measurement device (6) inducing eddy currents in the wayside structure at two spots along the travelling direction, measuring the variations of the magnetic field emitted by the wayside structure and determining position and speed by correlating the 2 measured signals known from U.S. Pat. No. 5,825,177 and a wayside coded tag (1) providing a coding recognizable by the onboard speed measurement device (6). The coded tag (1) consists of a bar (4) with several slots (3) in which metal blocks (2) of different sizes are mounted. The block sizes and positions are selected to represent a coding according to Quadrature Amplitude Modulation.

Abstract: An apparatus includes a test signal generation unit supplying test signals to an orthogonal modulator and a control unit that based on a result of decision by comparison and decision of detection results of a detector detecting envelopes of modulated signals output from the orthogonal modulator responsive to the test signals, derives adjustment values and a compensation value. An estimation means estimates a DC offset and an IQ mismatch of the orthogonal modulator, based on the derived compensation value. The test signals includes a first set including a first test signal (I1, Q1) and a second test signal (I2, Q2) having a predetermined relationship with the first test signal, and a second set of which in-phase and quadrature components have predetermined relationships respectively with in-phase and quadrature components of the first set.

Abstract: Differences in outputs from multiple terminals are easily measured.

Abstract: A modulation error measurement device according to the present invention receives a demodulated signal containing a demodulated I signal and a demodulated Q signal from a quadrature demodulator receiving an RF signal output by a quadrature modulator and applying the quadrature demodulation to the received RF signal, and measures a quadrature error corresponding to a phase difference between an I component and a Q component of the modulated signal. The quadrature modulator applies quadrature modulation to an original I signal (?1) and an original Q signal (?2) having frequencies different from each other.

Abstract: This invention deals with an advanced Real-time Grid Monitoring System (RTGMS) suitable for both single-phase and three-phase electric power systems. This invention provides an essential signal processing block to be used as a part of complex systems either focused on supervising and diagnosing power systems or devoted to control power processors interacting with the grid. This invention is based on a new algorithm very suitable for real-time characterization of the grid variables under distorted and unbalanced grid conditions. The main characteristic of this invention is the usage of a frequency-locked loop, based on detecting the grid frequency, for synchronizing to the grid variables. It results in a very robust system response in relation to existing technique based on the phase-angle detection since grid frequency is much more stable variable than the grid voltage/current phase-angle, mainly during grid faults.

Abstract: Sets of time domain data of respective frequency bands from Fd-1 to Fd-n of a periodic input signal Fs are acquired. Sets of the time domain data of the common frequency band are extracted from the sets of the time domain data of the frequency bands Fd-1 and Fd-2 in the acquired frequency bands. Correlativity between the sets of the time domain data of the common frequency band is determined while shifting time relationship between the sets each other to identify the sets of time domain data having correspondence relationship. The sets of the time domain data having the correspondence relationship in the time domain data of the adjacent frequency band Fd-1 and Fd-2 are converted to the sets of the frequency domain data respectively, and the sets of the frequency domain data are combined to produce one set of combined frequency domain data.

Abstract: This invention deals with an advanced Real-time Grid Monitoring System (RTGMS) suitable for both single-phase and three-phase electric power systems. This invention provides an essential signal processing block to be used as a part of complex systems either focused on supervising and diagnosing power systems or devoted to control power processors interacting with the grid. This invention is based on a new algorithm very suitable for real-time characterization of the grid variables under distorted and unbalanced grid conditions. The main characteristic of this invention is the usage of a frequency-locked loop, based on detecting the grid frequency, for synchronizing to the grid variables. It results in a very robust system response in relation to existing technique based on the phase-angle detection since grid frequency is much more stable variable than the grid voltage/current phase-angle, mainly during grid faults.

Abstract: A device (10) for the detection of quadrature signals of a signal unit (11; 21) has a common power supply line (VBATT_ A & B) and a common ground wire (GND), and emits at least two out-of-phase square wave signals (IA, IB; IS, ID) during operation for analyzing the same in an analysis unit (16), wherein both out-of-phase square wave signals (IA, IB; IS, ID) are applied to the common power supply line (VBATT _A & B) at different amplitudes, wherein the two out-of-phase square wave signals (IA, IB; IS, ID) are modulated onto the supply current (I0)), and wherein the analysis unit (16) is or can be connected to the power supply line.

Abstract: A modulation error measurement device according to the present invention receives a demodulated signal containing a demodulated I signal and a demodulated Q signal from a quadrature demodulator receiving an RF signal output by a quadrature modulator and applying the quadrature demodulation to the received RF signal, and measures a quadrature error corresponding to a phase difference between an I component and a Q component of the modulated signal. The quadrature modulator applies quadrature modulation to an original I signal (?1) and an original Q signal (?2) having frequencies different from each other.

Abstract: The traveling wave excitation system phase shifter chassis method and device of the invention is compact, inexpensive, and versatile when compared to customary methods for generating traveling wave excitation signals that would require using an equivalent number of commercial function generators. The method and device of the invention produces up to 56 simultaneous sine waves that are phase shifted with respect to one another.

Abstract: Methods and apparatuses are provided for performing direct quadrature sampling. One method for sampling quadrature baseband components of a bandpass signal includes receiving a bandpass signal, sampling the bandpass signal using a first sampling clock and a second sampling clock, where the first and the second sampling clocks have the same frequency and are offset by a predetermined phase, and aligning the sampled signals temporally to produce in-phase and quadrature samples corresponding to baseband in-phase and quadrature components. An apparatus for directly sampling baseband quadrature components of a bandpass signal is also presented, which includes a first analog-to-digital converter (ADC) configured to receive a bandpass signal, a second ADC configured to receive the bandpass signal, where the second ADC has a clock having a phase offset with respect to clock signal of the first ADC, and an interpolator coupled to the first ADC configured provide coincident samples.

Abstract: A phasemeter for estimating the phase of a signal. For multi-tone signals, multiple phase estimates may be provided. An embodiment includes components operating in the digital domain, where a sampled input signal is multiplied by cosine and sine terms to provide estimates of the inphase and quadrature components. The quadrature component provides an error signal that is provided to a feedback loop, the feedback loop providing a model phase that tends to track the phase of a tone in the input signal. The cosine and sine terms are generated from the model phase. The inphase and quadrature components are used to form a residual phase, which is added to the model phase to provide an estimate of the phase of the input signal. Other embodiments are described and claimed.

Abstract: Meter electronics (20) for processing sensor signals in a flow meter is provided according to an embodiment of the invention. The meter electronics (20) includes an interface (201) for receiving a first sensor signal and a second sensor signal and a processing system (203) in communication with the interface (201) and configured to receive the first sensor signal and the second sensor signal, generate a ninety degree phase shift from the first sensor signal, and compute a frequency from the first sensor signal and the ninety degree phase shift. The processing system (203) is further configured to generate sine and cosine signals using the frequency, and quadrature demodulate the first sensor signal and the second sensor signal using the sine and cosine signals in order to determine the phase difference.

Abstract: A phasemeter for estimating the phase of a signal. For multi-tone signals, multiple phase estimates may be provided. An embodiment includes components operating in the digital domain, where a sampled input signal is multiplied by cosine and sine terms to provide estimates of the inphase and quadrature components. The quadrature component provides an error signal that is provided to a feedback loop, the feedback loop providing a model phase that tends to track the phase of a tone in the input signal. The cosine and sine terms are generated from the model phase. The inphase and quadrature components are used to form a residual phase, which is added to the model phase to provide an estimate of the phase of the input signal. Other embodiments are described and claimed.

Abstract: A time of an event can be determined by acquiring an amplitude, at the time of the event, of at least two periodic timing signals that are out of phase with each other. The time of the event within a cycle of at least one of the timing signals can be determined as a function of the amplitudes of the timing signals. The phase angle and complex coordinates of at least one of the timing signals can be determined as a function of the amplitudes. The time of the event within a cycle of a timing signal can be determined as a function of the phase angle or complex coordinates of the timing signal at the time of the event.

Abstract: In order to provide a phase detector and a method of phase detection which are distinguished by greater sensitivity and simple implementability, at least one differential signal of two input signals (Ua; Ub) may be formed over at least one predefined period by means of a first subtracter (12), at least one maximum value of the at least one differential signal may be detected by means of a first peak detector (16) and at least one minimum value of the at least one differential signal may be detected by means of a second peak detector (18) and at least one further differential signal (Uout) may be formed from the at least one maximum value and the at least one minimum value by means of a second subtracter (14).

Abstract: The invention is directed to a digital phase detector that comprises a splitter and phase shifter to receive a signal of a device under test and produce a first signal that is substantially identical to the received signal and a second signal that is phase shifted relative to the first signal. A first analog-to-digital channel processes the first signal to produce an in-phase and quadrature signals. The second signal is processed by a second analog-to-digital channel to produce a second set of in-phase and quadrature signals. The two sets of in-phase and quadrature signals are used to determine a phase difference between the signal of the device under test and a local oscillator signal associated with the two analog-to-digital channels. The invention is further directed to a direct digital synthesizer that is capable of use within the digital phase detector and in other applications.

Abstract: Replica output buffers, having the same input/output characteristic as that of an output buffer, respond to the rise of a TEST signal generated by a test pulse generating circuit and causes an output signal to rise at a through rate according to voltage of an SL_SET signal, and causes an output signal to fall at a through rate according to voltage of a CNT signal. A phase comparing circuit makes a comparison between phases of the signals output from the replica output buffers, and outputs an UP signal or Down signal with a length corresponding to a phase difference to a delay control circuit. The delay control circuit changes the voltage of the CNT signal according to the UP signal and the DOWN signal, and adjusts a through rate at which a signal output from the output buffer falls.

Abstract: A method of eliminating unnecessary frequency components using a quadrature detector. The method includes converting an analog input signal into a digital signal f1(t), and the signal f1 (t) is delayed by a sampling time ? to form a signal f2 (t). Then, letting the reference frequency be ?0, the I- and Q-components in quadrature detection by the following expression: I={f2(t)*sin ?0t?f1(t)*sin ?0(t??)}/sin ?0? Q={f2(t)*cos ?0t?f1(t)*cos ?0(t??)}/sin ?0?.

Abstract: The invention relates to a device and a method for monitoring the connection of an electrical supply unit comprising voltage detection (32) detecting phase voltage (14), current detection (32) detecting phase voltages (38), a transformation unit (66) transforming the phase voltages (38) after conducting field-oriented regulation in at least one cross current (62), wherein a monitoring device (34) is provided to monitor at least one supply connection (28, 36) by means of which an electrical supply unit (32) is supplied, said monitoring unit evaluating the variation of the cross current (62) in order to monitor the connection.

Abstract: A method and circuit for achieving minimum latency data transfer between two mesochronous (same frequency, different phase) clock domains is disclosed. This circuit supports arbitrary phase relationships between two clock domains and is tolerant of temperature and voltage shifts after initialization while maintaining the same output data latency. In one embodiment, this circuit is used on a bus-system to re-time data from receive-domain, clocks to transmit-domain clocks. In such a system the phase relationships between these two clocks is set by the device bus location and thus is not precisely known. By supporting arbitrary phase resynchronization, this disclosure allows for theoretically infinite bus-length and thus no limitation on device count, as well as arbitrary placement of devices along the bus. This ultimately allows support of multiple latency-domains for very long buses.

Abstract: A phase region detector receives in-phase signal I representing in-phase component and quadrature signal Q representing quadrature component of a first signal and second signal respectively, equally divides an angle range of 2 ? into a plurality M of three or more of angle regions preliminarily, on virtual quadrature coordinates, sequentially assigns angle region numbers in each of the angle regions, detects the angle region corresponding to the variation of phase of the second signal starting from the phase of the first signal, and issues the angle region number assigned in this angle region. A phase displacement detector issues a signal expressing the time change of the variation of the phase from the change corresponding to the time of the angle region number. An out-of-bounds detector receives a signal issued from the phase displacement detector, and issues an out-of-bounds signal including the out-of-bounds direction every time the variation of the phase exceeds a predetermined value.

Abstract: A current comparator technique is applied to four-terminal resistance measurements for obtaining a highly accurate AC resistance bridge at power frequencies of 50 Hz to 60 Hz. Active circuits are used to establish equal voltage drops between the potential terminals of the two resistances being compared. The bridge is suitable for measuring resistances from 10 &mgr;&OHgr; to 100 k&mgr;&OHgr;. A cascading technique using two two-stage current transformers provides extension of the ratio range to 100,00,000 with a maximum applied current of 10,000 A. The bridge features measurement with a resolution of 0.1×10−6. The total combined uncertainty (2&sgr;) of the bridge including the range extenders, at power frequencies, is estimated to be less than 5 &mgr;&OHgr;/&OHgr;.

Abstract: A phase delay characteristic measuring apparatus includes an in-phase component calculating means for outputting a correlation value between input sampling data of the input signal and the output signal and ideal sine waveform data as a baseband I signal (in-phase component), a quadrature component calculating means for outputting a correlation value between the input sampling data of the input signal and the output signal and ideal cosine waveform data as a baseband Q signal (quadrature component), a phase angle calculating means for outputting phase angles of the input signal and the output signal based on the baseband I signal and the baseband Q signal, and a phase delay calculating means for calculating an amount of phase delay of the tested device from the phase angles of the input signal and the output signal.

Abstract: A receiving level measuring circuit, which is capable of improving measuring accuracy of a receiving level by correcting phase rotation caused by a frequency error between oscillators included in a transmitter and a receiver and by inhibiting an inappropriate correction when no desirable wave exists and is adapting to a receiver configuration having a plurality of antennas (branches), wherein a desirable/interference wave detection unit detects a frequency error vector, an adder, a frequency error averaging unit, and an arctangent operation unit add up and average the frequency error vectors and performs a unit conversion of the resultant value, a frequency error correction table previously stores a correction value corresponding to the frequency error so as to get the correction value corresponding to the frequency error, an adder adds up a plurality of desirable wave components, and a frequency error correction unit corrects the desirable wave component by using the correction value.

Abstract: Analyzing a swept spectrum signal formed by mixing a ramping local oscillator and an input signal to generate an IF signal, the resulting IF signal having a phase change with respect to the input signal, the phase change including a quadratic portion. For analysis, the IF signal is processed such that the quadratic component of the phase change is removed. The quadratic component of the phase change is removed with a complex filter.

Abstract: A receiving level measuring circuit, which is capable of improving measuring accuracy of a receiving level by correcting phase rotation caused by a frequency error between oscillators included in a transmitter and a receiver and by inhibiting an inappropriate correction when no desirable wave exists and is adapting to a receiver configuration having a plurality of antennas (branches), wherein a desirable/interference wave detection unit detects a frequency error vector, an adder, a frequency error averaging unit, and an arctangent operation unit add up and average the frequency error vectors and performs a unit conversion of the resultant value, a frequency error correction table previously stores a correction value corresponding to the frequency error so as to get the correction value corresponding to the frequency error, an adder adds up a plurality of desirable wave components, and a frequency error correction unit corrects the desirable wave component by using the correction value.

Abstract: A frequency detection circuit is disclosed that employs a phase lock loop circuit in operative cooperation with a microprocessor. The microprocessor provides a control signal to an oscillator of the phase lock loop circuit so as to control its free-running frequency. The microprocessor has prestored quantities that represents predetermined parameters for measuring the frequency components contained in a tone burst transmitted from a sonobuoy. The microprocessor provides an output signal if the measured parameters correspond to predetermined and desired parameters. The microprocessor has predetermined parameters for measuring the length of the tone burst. The microprocessor provides a serial output signal transmitting the frequency and tone burst length measurements.

Abstract: Transistors (12a, 12b) turn on and off with mutually opposite phase input signals. Capacitors (16a, 16b) discharge when the transistors (12a, 12b) turn on, and capacitors (16a, 16b) are charged by constant current from constant current sources (18a, 18b) when the transistors (12a, 12b) turn off. As a result, a gradually rising voltage is obtained at the positive input ends of comparators (14a, 14b) while the input signals are L. By comparing this with fixed voltages of reference sources (20a, 20b), signals having rise timing shifted from input signals by 90° are obtained. The outputs of the comparators (14a, 14b) are mutually shifted by 180°, and at the rise of these outputs, an RS flip-flop (22) is set and reset so that signals delayed in phase by 90° with respect to the input signals are obtained at its outputs.

Abstract: An engagement detection circuit for a clock recovery circuit consisting of a phase detector (3), a counter element (6) and a flip-flop (8). By employing a low-pass element (12) and a trigger element (13) connected downstream, a preliminary and a final engagement of a phase control circuit can be detected with the engagement detection circuit. This provides a clock recovery circuit for controlling a phase control loop with a phase detector (20), a loop filter (21), a voltage-controlled oscillator (22) and a controllable frequency divider (23).

Abstract: A method and apparatus for determining the instantaneous power of a sinusoid signal is provided. Generally speaking, the apparatus of the present invention determines the instantaneous power of a sinusoid signal without the need for filtering. This is accomplished based on the trigonometric identity sin2x+cos2x=1. By first splitting the incoming signal into two signals so that the resultant signals are 90 degrees out of phase with each other, and subsequently squaring the split signals and adding the squared split signals, the AC component of the original signal is effectively removed, leaving a DC representation of the square of the amplitude of the original signal without any residual AC component. The square of the amplitude of the original signal is directly proportional to the instantaneous power of the original signal.

Abstract: A method and apparatus for generating an accurate, stable phase shift (b) in a sinusoidal signal employs fast analog multiplication to implement the trigonometric relationship sin(&ohgr;t+b)=sin(&ohgr;t)cos(b)+cos(&ohgr;t)sin(b). Cos(&ohgr;t) is generated by accurately shifting a signal sin(&ohgr;t) through 90° using a delay line, for example. Sin(b) and cos(b) are dc signals generated by digital to analogue conversion, using a demanded phase shift (b) whose sine and cosine are obtained from look-up tables. A controller for controlling a phase shift in an rf cavity is also disclosed and operates on the basis of the same trigonometrical principle. The amplitude of the signals in the rf cavity is also controllable; fast analogue multipliers are again employed to scale the signal amplitude to a nominal fixed value such as 1 volt.

Abstract: The present invention provides a wide band IQ splitting apparatus suitable for using in a spectrum analyzer. A quadrature oscillator 30 generates a pair of quadrature signals. An amplitude and phase adjuster 32 receives the quadrature signals and adjusts the balances of the amplitude and the phase between them. An analog splitter 20 mixes an analog IF signal with the pair of quadrature signals for splitting the analog IF signal into analog I and Q signals. First and second analog to digital converters 22 and 24 convert the analog I and Q signals into digital I and Q signals, respectively. A control and processing circuit detects the imbalances of the amplitude and phase between the digital I and Q signals for controlling the amplitude and phase adjuster 32. The amplitude and phase adjuster 32 is previously calibrated. For this first calibration, the analog splitter 20 receives a first calibration signal instead of the analog IF signal.