Abstract: A passive vector modulator (PVM) includes a divider that splits an input signal into a first divided signal and a second divided signal 90° apart in phase. The PVM includes a switched transformer phase shifter including primary windings to form first primary windings and second primary windings receiving the first divided signal and the second divided signal respectively. First secondary windings are coupled to the first primary windings, the first secondary windings being center-tapped and outputting first and second phase shifted output signals, phase shifted 180° and 0° respectively. Second secondary windings are coupled to the second primary windings, the second secondary windings being center-tapped and outputting third and fourth phase shifted signals, phase shifted 270° and 90° respectively. The PVM includes a switch configured to receive the phase shifted output signals. The switch selectively outputs one of the phase shifted output signals, or a combination, from the PVM.

Abstract: A clock frequency divider circuit and a receiver are provided. The clock frequency divider circuit includes a reset retimer circuit configured to receive a reset signal and a clock signal, output a reset buffer signal of a differential signal pair obtained by buffering the reset signal, and output a reset synchronization signal obtained by synchronizing the reset signal with the clock signal, a clock buffer circuit configured to receive the clock signal and the reset synchronization signal and output a clock buffer signal of a differential signal pair obtained by buffering the clock signal, and an IQ divider circuit configured to output first through fourth output signals having different phases based on the reset buffer signal and the clock buffer signal.

Abstract: A multiphase signal generator includes an input port. Furthermore, the multiphase signal generator includes a plurality of phase shifters. Each phase shifter of the plurality of phase shifters is configured to provide an identical phase shift ??. At least one phase shifter is connected to the input port. Furthermore, the multiphase signal generator includes a first phase interpolator and at least a second phase interpolator. Each phase interpolator has a respective output terminal. Each phase interpolator is configured to weight a phase of a signal at a respective first input terminal of the phase interpolator with a respective first weighting factor wi,1 and to weight a phase of another signal at a respective second input terminal of the phase interpolator with a respective second weighting factor wi,2 to generate an interpolated phase signal at the respective output terminal of the phase interpolator. A first subset of the plurality of phase shifters includes n>1 serially connected phase shifters.

Abstract: The embodiments described herein provide systems and methods for digital correction in low intermediate frequency (IF) receivers. Specifically, the embodiments described herein use digital correction techniques that can correct for signal distortions in low IF receivers caused by I-Q imbalance, including both I-Q magnitude imbalance and I-Q phase imbalance. In general, the embodiments described herein are implemented to at least partially cancel an image of a blocking signal in the complex digital signal. Such a cancellation can be implemented to at least partially cancel an image of blocking signal where that image occurs at or near the intermediate frequency. In one embodiment, a corrector is implemented in a low RF receiver and is configured to receive a complex digital signal that includes an image of a blocking signal. Such a low RF receiver can further include a corrector controller to selectively enable the corrector.

Abstract: Apparatuses and methods for providing multiphase clock signals are described. An example apparatus includes first, second, third and fourth clocked inverters, first and second clock terminals, and first and second latch circuits. An input node and an output node of the first clocked inverter is coupled respectively to an output node of the fourth clocked inverter and an input node of the second clocked inverter. An input node and an output node of the third clocked inverter is coupled to an output node of the second clocked inverter and an input node of the fourth clocked inverter. The first and second clock terminals are supplied respectively with first and second clock signals. The first latch is coupled between the output nodes of the first and third clocked inverters, and the second latch circuit is coupled between the output nodes of the second and fourth clocked inverters.

Abstract: An FM-CW radar includes a high frequency circuit that receives a reflected wave from a target, and a signal processing unit that converts an analog signal generated by the high frequency circuit into a digital signal and detects at least a distance to the target and velocity of the target. The high frequency circuit includes a VCO that receives a modulation voltage from the signal processing unit and generates a frequency-modulated high frequency signal. The signal processing unit includes an LUT that stores default modulation control data. The signal processing unit calculates frequency information from phase information of output of the VCO, and updates the data stored in the LUT with correction data that is generated by using a result of the calculation.

Abstract: The present invention relates generally to integrated circuits. More particularly, the present invention provides a circuit and method for a CMOS interpolator for an output clock signal with a desirable phase for a high speed serializer/deserializer device. In a specific embodiment, the present invention provides a phase interpolator device that mixes phase-shifted clock signals according to a predetermined weight values at predetermined time intervals. There are other embodiments as well.

Abstract: A FMCW radar receiver includes a LO providing a chirped LO signal, an in-phase (I) channel for outputting I-data and a quadrature (Q) channel for outputting Q-data. A dynamic correction parameter generator generates IQ phase correction values (P[n]s) and IQ gain correction values (G[n]s) based on a frequency slope rate of the chirped LO signal for generating during intervals of chirps including a first sequence of P[n]s and G[n]s during a first chirp and a second sequence of P[n]s and G[n]s during a second chirp. An IQ mismatch (IQMM) correction circuit has a first IQMM input coupled to receive the I-data and a second IQMM input receiving the Q-data, and the P[n]s and G[n]s. During the first chirp the IQMM correction circuit provides first Q?-data and first I?-data and during the second chirp the IQMM correction circuit provides at least second Q?-data and second I?-data.

Abstract: A digital phase shifter includes a logic control circuit, at least four current digital-to-analog converters, at least four amplifiers, and a vector summation circuit. The logic control circuit generates four N-bit digital phase shift control signals according to an (N+2)-bit digital control source signal, and respectively inputs the four N-bit digital phase shift control signals to the four current digital-to-analog converters. The four current digital-to-analog converters are respectively connected in series with the four amplifiers, to implement selection and amplification on four orthogonal input signals, and the vector summation circuit synthesizes amplified signals that are output by the four amplifiers, to obtain a signal having a 360 degree (°) phase shift range.

Abstract: An active I/Q generator circuit comprises an input node for receiving a reference oscillation signal. The circuit has an I-output and a Q-output for respectively outputting an I-signal and a Q-signal. A first active component is electrically coupled to the input node and arranged to amplify the reference oscillation signal and to output an amplified reference oscillation signal. A second active component is electrically coupled to the first active component to receive the amplified reference oscillation signal. The second active component is arranged to generate, based on the amplified reference oscillation signal, an in-phase signal and a, with respect to the in-phase signal, phase shifted signal, the second active component electrically coupled to the in-phase signal output for providing the in-phase signal and electrically coupled to the quadrature-phase output for providing the phase-shifted signal.

Abstract: Circuits, devices and methods are disclosed, including a phase shifter configured to provide a bypass state, a single first-handed quarter-wave state, a double first-handed quarter-wave state, or a single second-handed quarter-wave state utilizing two or less inductors. In some implementations, a phase shifter is disclosed to provide a first node and a second node, a first switchable path having a first inductance and a second inductance arranged in series between the first and second nodes, a capacitive grounding path implemented on each side of each of the first and second inductances, at least one of the capacitive grounding paths configured as a switchable capacitive grounding path, and a reconfiguring circuit assembly configured to allow the phase shifter to provide a plurality of quadrant phase shifts utilizing the first and second inductances and the at least one switchable capacitive grounding path.

Abstract: Disclosed are a calibration method and a calibration circuit. The calibration method and the calibration circuit effectively calibrate the mismatches between the first signal path and the second signal path of a receiver by calibrating a plurality of tap coefficients of a finite impulse response filter configured in the second signal path and optimizing the tap coefficients. The calibration and optimization for the tap coefficients of the finite impulse response filter is according to differences between the electrical characteristics the analog-to-digital convertor and the LPF in the first signal path and differences between the analog-to-digital convertor and the LPF in the second signal path. These differences are obtained when the data reception has not yet started by the receiver (that is, when the receiver is working in a training mode).

Abstract: A variable phase shifter. The variable phase shifter includes: a transmission line that outputs quadrature signals from a pair of output ports in response to an input signal of a specific frequency; a synthesizer that includes a first transistor connected to a first port of the pair of output ports and a second transistor connected to a second port of the pair of output ports, and that on input of the input signal takes signals output from the pair of output ports of the transmission line with a phase according to their respective load impedances and employs the first and the second transistors to amplify and combine the signals; and a phase controller that controls the phase of the output signal that is combined and output by the synthesizer by controlling the amplification operation of each of the first and second transistors of the synthesizer.

Abstract: A variable phase shifter. The variable phase shifter includes: a transmission line that outputs quadrature signals from a pair of output ports in response to an input signal of a specific frequency; a synthesizer that includes a first transistor connected to a first port of the pair of output ports and a second transistor connected to a second port of the pair of output ports, and that on input of the input signal takes signals output from the pair of output ports of the transmission line with a phase according to their respective load impedances and employs the first and the second transistors to amplify and combine the signals; and a phase controller that controls the phase of the output signal that is combined and output by the synthesizer by controlling the amplification operation of each of the first and second transistors of the synthesizer.

Abstract: Circuits, architectures, a system and methods for providing quadrature output signals. The circuit generally includes a quadrature signal generator and a plurality of frequency dividers. The plurality of frequency dividers are each configured to receive a plurality of quadrature signal generator outputs at a first frequency and provide a plurality of outputs at a second frequency. The method generally includes providing a plurality of quadrature signals at a first frequency and dividing the first frequency of the quadrature signals by n, wherein n is an odd integer of at least 3, thereby providing a plurality of divided-by-n quadrature outputs at a second frequency, wherein the second frequency is about equal to the first frequency divided by n. The present disclosure further advantageously improves quadrature signal generation accuracy, reliability and/or performance.

Abstract: An integrated circuit comprising an inductor arrangement, the arrangement comprising: four inductors adjacently located in a group and arranged to define two rows and two columns, wherein: the integrated circuit is configured to cause two of those inductors diagonally opposite from one another in the arrangement to produce an electromagnetic field having a first phase, and to cause the other two of those inductors to produce an electromagnetic field having a second phase, the first and second phases being substantially in antiphase.

Abstract: Signal-alignment circuitry, comprising: phase-rotation circuitry connected to receive one or more input clock signals and operable to generate therefrom one or more output clock signals; and control circuitry operable to control the amount of phase rotation applied by the phase-rotation circuitry to carry out a plurality of alignment operations, the alignment operations comprising: one or more first operations each comprising rotating one or more of said output clock signals relative to one or more of the other said output clock signals, to bring a phase relationship between said output clock signals, or clock signals derived therefrom, towards or into a given phase relationship; and one or more second operations each comprising rotating all of said output clock signals together, to bring a phase relationship between said output or derived clock signals and said input clock signals or an external-reference signal towards or into a given phase relationship.

Abstract: Phase offset cancellation circuit and associated clock generator, include a first modifying phase interpolator and a second modifying phase interpolator, and provide a first modified clock and a second modified clock according to a first to a fourth input clocks; wherein the first and the third clocks are of opposite phases. The first modifying phase interpolator performs equal phase interpolation between the first and the second input clocks to generate the first modified clock, and the second modifying phase interpolator performs equal phase interpolation between the third and the fourth input clocks to generate the second modified clock, such that a phase difference between the first modified clock and the second modified clock is of substantially 90 degrees, against phase offsets between the first to the fourth input clocks.

Abstract: Methods and apparatuses for high rotation rate low I/O count phase interpolation are disclosed, including techniques to reduce redundant phase interpolation coding and method steps by modifying phase mapping and generation with pluralities of amplifiers. I/O reduction count is achieved while maintaining resolution and allowing scalability in phase interpolation. Control circuits include techniques to interpolate phases at a high rotation rate while reducing discontinuities and risk for logic hazards.

Abstract: An apparatus comprising a frequency divider comprising a first latch configured to receive a first clock signal and a complement of the first clock signal and to generate a first latch first output, and a second latch coupled to the first latch in a toggle-flop configuration, a first output circuit comprising a p-channel transistor, wherein the gate of a p-channel transistor is configured to receive the first clock signal, and a n-channel transistor, wherein the drain of the p-channel transistor is directly connected to the drain of a n-channel transistor, wherein the gate of the n-channel transistor is configured to receive the first latch first output, wherein the source of the n-channel transistor is configured to receive the complement of the first clock signal, and wherein the first output circuit is configured to generate an in-phase reference signal, and a second output circuit configured to generate a quadrature signal.

Abstract: An automatic quadrature network with amplitude and phase detection produces quadrature signals for an input oscillator signal, the quadrature signals being equal in amplitude and having ideal quadrature phase between them. An RC circuit provides one quadrature path, and a CR circuit provides another quadrature path. The outputs from the RC/CR circuits are amplitude detected to produce an amplitude control signal. The outputs also are amplitude limited, and the phase between the limiter outputs is detected to produce a phase control signal. The amplitude and phase control signals are combined to generate respective control signals for the RC/CR circuits to automatically align them so that the quadrature signals are of equal amplitude and ideal quadrature phase.

Abstract: An apparatus for dividing a frequency by 1.5 to produce a quadrature signal is disclosed. The apparatus includes a divider that receives a differential input signal with a first frequency and two phases and creates a six-phase signal at a second frequency. The second frequency is the first frequency divided by 3. The apparatus also includes precision phase rotation circuitry that receives the six-phase signal and produces an eight-phase signal. The apparatus also includes a doubler that receives the eight-phase signal and produces a quadrature signal. The quadrature signal has a third frequency that is the first frequency divided by 1.5.

Abstract: Disclosed herein are systems and methods for accurate removal of I/Q mismatch in received signals of an analog FM receiver. The analog FM receiver includes a down-converter, a calibration circuit that estimates I/Q mismatch values, and a compensation circuit that uses the estimated mismatch values to reduce the effects of I/Q mismatch. In one aspect, the calibration circuit uses an adaptive dual-parameter compensation scheme to iteratively correct the received signals by approximating a coefficient value and an amplitude value that minimize the signals' amplitude variation from the amplitude value. In another aspect, phase and amplitude mismatch parameters can be determined using the coefficient value.

Abstract: An exemplary phase interpolator includes a first to a fourth differential pair. Each of the differential pairs includes a first and a second transistor and a stabilizing capacitor connected between a source coupled node and a reference voltage. The phase interpolator also includes a plurality of current sources and a group of switches to switch connections between the source coupled nodes of the differential pairs and the current sources so that (i) a first operating current is supplied to a first selected one of the first and second differential pairs and (ii) a second operating current is supplied to a second selected one of the third and fourth differential pairs. Drains of the first transistors in the differential pairs are commonly connected and drains of the second transistors in the differential pairs are commonly connected to form a first and a second output node so that a differential output signal is output.

Abstract: The present invention provides an improvement of a 4-quadrant clock phase interpolator design to allow independent rotation of the output clocks in steps of 90°. This feature is useful in clock/data recovery where the 90° “jumps” can be used as a coarse control to re-align the data capture clock to achieve any desired data word alignment and/or receive bus clock alignment. The phase interpolator has a switching circuit comprising a single level of switches; a set of four transistor loads; and a set of four current sources operable to be switched by the switching circuit through to any of the set of four transistor loads.

Abstract: An apparatus includes a drive signal circuit for MEMS sensor. The drive signal circuit includes an input configured to receive a voltage signal representative of charge generated by the MEMS sensor, a phase-shift circuit electrically coupled to the input and configured to phase shift an input signal by substantially ninety degrees, and a comparator circuit with hysteresis. An input of the comparator is electrically coupled to an output of the phase-shift circuit and an output of the comparator circuit is electrically coupled to an output of the drive signal circuit. A feedback loop extends from the output of the drive signal circuit to the input of the phase-shift circuit and is configured to generate a self-oscillating signal at an output of the drive signal circuit. An output signal generated by the drive signal circuit is applied to a drive input of the MEMS sensor.

Abstract: Phase offset cancellation circuit and associated clock generator, include a first modifying phase interpolator and a second modifying phase interpolator, and provide a first modified clock and a second modified clock according to a first to a fourth input clocks; wherein the first and the third clocks are of opposite phases. The first modifying phase interpolator performs equal phase interpolation between the first and the second input clocks to generate the first modified clock, and the second modifying phase interpolator performs equal phase interpolation between the third and the fourth input clocks to generate the second modified clock, such that a phase difference between the first modified clock and the second modified clock is of substantially 90 degrees, against phase offsets between the first to the fourth input clocks.

Abstract: A 0-to-90-degree phase shifter (13) includes a voltage-variable power supply (16), a transistor (17), a 90-degree divider (18), gain-variable amplifiers (19) (19-1 and 19-2), and a combiner (20). The 90-degree divider (18) divides an input signal into a signal to which a 90-degree phase is given and a signal to which no phase is given, and outputs the divided signals to the gain-variable amplifiers (19). The gain-variable amplifiers (19) (19-1 and 19-2) output signals whose amplitudes are changed according to a phase control amount to the combiner (20). The combiner (20) combines the signals input from the two gain-variable amplifiers (19) and outputs the combined signal. The impedance between the source and the drain of the transistor connected to the isolation port of the 90-degree divider (18) can be changed as appropriate.

Abstract: Exemplary embodiments are directed to systems, methods, and devices for generating quadrature clock signals. A device may include a plurality of dynamic logic cells and a plurality of inverters. Each inverter of the plurality of inverters may be coupled to at least two dynamic logic cells of the plurality of dynamic logic cells. Each inverter may be configured to output a twenty-five percent duty cycle clock signal.

Abstract: A voltage generator (400) includes a resistor ladder including resistors (4000-4008) which divide a supplied voltage to generate a plurality of reference voltages, a resistor (4009) provided between a power supply voltage (VCC) and one terminal of the resistor ladder, and a resistor (4010) provided between a power supply voltage (VEE) and the other terminal of the resistor ladder.

Abstract: A vector sum phase shifter includes a 90° phase shifter (1) which generates an in-phase signal (VINI) and a quadrature signal (VINQ) from an input signal (VIN), a four-quadrant multiplier (2I) which changes the amplitude of the in-phase signal (VINI) based on a control signal (CI), a four-quadrant multiplier (2Q) which changes the amplitude of the quadrature signal (VINQ) based on a control signal (CQ), a combiner (3) which combines the in-phase signal (VINI) and the quadrature signal (VINQ), and a control circuit (4). The control circuit (4) includes a voltage generator which generates a reference voltage, and a differential amplifier which outputs the difference signal between a control voltage (VC) and the reference voltage as the control signal (CI, CQ). The differential amplifier performs an analog operation of converting the control voltage (VC) into the control signal (CI, CQ) similar to a sine wave or a cosine wave.

Abstract: A clock phase shift detector circuit may include a phase detector that receives a first and a second clock signal, whereby the phase detector generates a phase signal based on a phase difference between the first and the second clock signal. A first integrator is coupled to the phase detector, receives the phase signal, and generates an integrated phase signal. A second integrator receives the first clock signal and generates an integrated first clock signal. A comparator is coupled to the first and the second integrator, whereby the comparator receives the integrated phase signal and the integrated first clock signal. The comparator may then generate a control signal that detects a change between the phase difference of the first and the second clock signal and an optimized phase difference based on an amplitude comparison between the integrated phase signal and the integrated first clock signal.

Abstract: A clock phase shift detector circuit may include a phase detector for generating a phase signal based on a phase difference between first and second clock signals. A current mirror having a first, a second, and a third integrator may be coupled to the phase detector, whereby the first integrator integrates the first clock signal and generates a first voltage, the second integrator integrates the first clock signal and generates a second voltage, and the third integrator integrates the phase signal and generates a third voltage. A first comparator receives the first and the third voltage, and generates a first control signal. A second comparator receives the second and the third voltage, and generates a second control signal. The first and second control signals may detect a change between the phase difference of the first and the second clock signal and an optimized phase difference.

Abstract: The present invention provides an apparatus and method of generating a set of 8 clock signals nominally spaced at equal 45° intervals by phase interpolation from a set of 4 quadrature reference clocks. The scheme is useful for clock generation for data capture in an oversampled clock/data recovery (CDR) system where the frequency of data sampling is twice that of the frequency of reference clock edges.

Abstract: A ring oscillator including a plurality of buffer units, each of which has a cross-coupled structure, for generating clock signals using a bias voltage having a predetermined voltage level applied thereto, wherein the clock signals have a swing width corresponding to the bias voltage.

Abstract: A phased array architecture configured for current reuse is disclosed. In an exemplary embodiment, an apparatus includes a current mode phase rotator (PR) module configured to generate phase shifted in-phase (I) and quadrature-phase (Q) current signals, and a current mode residual sideband (RSB) correction module configured to correct residual sideband error associated with the phase shifted I and Q current signals. The RSB correction module and the PR module form a phased array element configured to reuse a DC supply current.

Abstract: A phase shifter comprises a differential quadrature all-pass filter (QAF) including a balanced input port and two balanced output ports. A quadrature phase shift is manifested between the balanced output ports. The phase shifter also comprises a resistance-capacitance polyphase filter (PPF) section defining two balanced input ports and two balanced output ports. The balanced input ports of the PPF are coupled to the balanced output ports of the QAF. The combination exhibits broad bandwidth and relatively low ohmic loss.

Abstract: In one embodiment of the invention, a method is disclosed to generate a clock output signal with selected phase. The method includes selecting a phase delay for the clock output signal; charging a capacitor with a first weighted current during a first phase input clock, charging the capacitor with a second weighted current during a portion of a second phase input clock, and determining if a voltage across the capacitor is greater than or equal to a threshold voltage to generate a first edge of the clock output signal with the selected phase delay. The first weighted current may have a weighting of N out of M to charge the capacitor with a predetermined rate of change in voltage in response to the selected phase delay. The second weighted current may have a weighting of M out of M to charge the capacitor with a constant rate of change.

Abstract: Provided is a time-domain voltage comparator including a voltage-time converter. The voltage-time converter includes a conversion unit and an output unit. The conversion unit includes a first MOS transistor which shifts a voltage level of the first detection node according to an external first voltage signal, and a second MOS transistor which shifts a voltage level of the second detection node according to an external second voltage signal. The output unit generates first and second output signals in response to voltages of the first and second detection nodes. The output unit determines a shifted time of the first output signal according to a voltage level of the first detection node and determines a shifted time of the second output signal according to a voltage level of the second detection node.

Abstract: A display apparatus includes a gate driver which sequentially outputs a gate signal at a high state in response to a gate control signal and a data driver which converts image data into a data signal in response to a data control signal. The display apparatus further includes a display panel which includes a plurality of gate lines which sequentially receive the gate signal, a plurality of data lines which receive the data signal and a plurality of pixels connected to the gate and data lines and which receive the data signal in response to the gate signal to display an image. The polarity of the data signal is inverted after the gate signal transitions to a low state.

Abstract: A nonlinear filter includes: a determination unit that determines, based on I and Q signals inputted into the determination unit, whether or not to perform pulse insertion; a rotation detector that detects a rotation direction of the I and Q signals on an IQ plane with respect to the origin of the IQ plane; a pulse generator that generates, when the determination unit determines to perform the pulse insertion, a pulse of which at least one of the direction and the magnitude is determined in accordance with at least the detected rotation direction; and an adder that inserts the pulse into the I and Q signals and outputs resultant I and Q signals.

Abstract: A stabilized quadrature RC/CR phase shifting network for generating quadrature RF and microwave signals. The network uses offset biasing of postamplifiers following the phaseshifter to fine tune quadrature-phase, and further uses an output quadrature-phase detector to stabilize quadrature-phase with negative feedback by using the quadrature-phase error signal to drive the quadrature-phase fine tuning control. In an alternative embodiment, the stability of quadrature-phase can be enhanced without the output quadrature-phase detector by making the quadrature-phase fine tuning control dependent upon the amplitude-difference negative feedback error signal.

Abstract: In at least one example embodiment, a phase signal generating apparatus includes a phase signal generator and phase controller. The phase signal generator is configured to receive a plurality of first phase signals and a plurality of second phase signals, adjust a phase difference between the plurality of first phase signals and the plurality of second phase signals and generate a plurality of adjusted first phase signals and a plurality of adjusted second phase signals, based on a switch control signal and a phase control signal, a phase difference between the plurality of adjusted first phase signals and the plurality of adjusted second phase signals being the adjusted phase difference. The phase controller is configured to generate the switch control signal and the phase control signal based on phase information for the plurality of first phase signals and the plurality of second phase signals.

Abstract: Clock generator embodiments are provided to generate half-rate I and Q clock signals. The generators are configured to insure fan-out limitations, to insure correct phasing at startup, to reduce the number of signal inverters in a critical path, and to reduce the total number of inverter structures to thereby substantially extend generator operational frequency. An exemplary generator embodiment requires only two tri-state inverters and four inverters. These clock generators are particularly suited for variety of electronic systems such as high speed data serializers.

Abstract: Phase shifting circuitry is provided for phase shifting at least one of first and second quadrature components of a data signal. The circuitry includes a first phase shifter adapted to phase shift, by a first phase angle, the first quadrature component by adding together weighted versions of the first and second quadrature components.

Abstract: According to one embodiment, an IQ signal generation circuit includes an RC poly-phase filter, a resistive load circuit and the transconductance amplifier. The RC poly-phase filter has first to fourth input terminals and first to fourth output terminals. The first and second input terminals receive first signals with a phase difference of 0°. The third and fourth input terminals receive second signals with a phase difference of 180°. The first to fourth output terminals output signals with phase differences of 0°, 90°, 180° and 270°. The resistive load circuit is connected between the first to fourth output terminals and a power supply terminal. The transconductance amplifier is connected between the first to fourth input terminals and a reference voltage terminal. The transconductance amplifier receives input signals, amplifies the input signals and generates the amplified signals to the first to fourth input terminals.

Abstract: The present invention is a controllable input impedance RF mixer, which when fed from a high impedance source, such as a current source, provides a high quality factor (Q) impedance response associated with an impedance peak. The high-Q impedance response may be used as a high-Q RF bandpass filter in a receive path upstream of down conversion, which may improve receiver selectivity and replace surface acoustic wave (SAW) or other RF filters. The present invention uses polyphase reactive circuitry, such as capacitive elements, coupled to the down conversion outputs of an RF mixer. The RF mixer mixes RF input signals with local oscillator signals to translate the impedance of the polyphase reactive circuitry into the RF input impedance of the RF mixer. The RF input impedance includes at least one impedance peak. The local oscillator signals are non-overlapping to maximize the energy transferred to the polyphase reactive circuitry.

Abstract: An apparatus and method for multi-phase clock generation are disclosed. One embodiment of the apparatus includes a module generating first and second intermediate signals delayed from first edges of a clock signal having a first frequency. Each of the first and second intermediate signals has a second frequency that is half of the first frequency. The first and second intermediate signals have a phase difference of 180° from each other. The apparatus also includes a first delay line delaying the first intermediate signal by a first delay amount; a second delay line delaying the first intermediate signal by a second delay amount; a third delay line delaying the second intermediate signal by a third delay amount; and a fourth delay line delaying the second intermediate signal by a fourth delay amount. The apparatus also includes a closed feedback loop for detecting and adjusting the second and fourth delay amount.

Abstract: A phase shift circuit that includes two, rather than four, delay chains and corresponding selectors is described. This provides a significant area savings and reduces the intrinsic delay of the phase shift circuit, which is particularly beneficial for embodiments in which there is no intrinsic delay matching. In one implementation, the phase shift circuit includes a first delay circuit and a matching delay circuit. The first delay circuit provides a first delay that includes a first intrinsic delay and a first intentional delay. The delay matching circuit provides a matching delay that matches the first intrinsic delay. In one implementation, the phase shift circuit also includes a second delay circuit to provide a second delay that includes a second intrinsic delay and second intentional delay, where the second intrinsic delay matches the first intrinsic delay and the second intentional delay is half as long as the first intentional delay.

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.