A feeding and reversing mechanism for a strapping machine includes a forward-reverse wheel assembly and a tension wheel assembly which are mounted on a base and arranged in such a way to provide larger contact areas between a strapping band and the two wheel assemblies. The feeding and reversing mechanism further includes first and second spring units. The first spring unit helps to keep a suitable gap between an active wheel and a passive wheel of the tension wheel assembly for the strapping band to pass through. The second spring unit helps to move the passive wheel toward the active wheel of the tension wheel assembly, so that the strapping band can be clamped between the passive wheel and the active wheel tightly to facilitate reversing and tightening of the strapping band.

A method for regulating a web tension in a processing machine for processing a product web, in particular a shaftless printing press, includes separating a first product-web section from a second product-web section by a delay section. The web tensions in the first and second product-web sections are influenced by first and second actuators, respectively. To regulate the web tension in the first product-web section, the method further includes defining a regulation output value from which an actuating command for the first actuator is derived. An actuating command for the second actuator is defined from the regulation output value and a delay element to decouple the web tension in the second product-web section from the regulation of the web tension in the first product-web section. The delay element delays the effect of the regulation output value on the actuating command for the second actuator by a delay time.

A stock feeder for woodworking equipment includes a base, a cross clamp, a horizontal bar unit, a vertical bar unit, a feeding unit, and an electrical unit. The electrical unit has an electrical unit main body and a variable-frequency drive. The electrical unit main body has a first housing, a plurality of heat dissipation grooves provided on the outer periphery of the first housing, and a power fan which is independently mounted on a top portion of the first housing and in communication with the heat dissipation grooves. The variable-frequency drive has a second housing, a variable-frequency circuit sealed in the second housing, and a control panel exposed outside the second housing. The second housing has an outer surface provided with a plurality of heat dissipation slots corresponding in position to and in communication with the heat dissipation grooves of the electrical unit main body.

A tape feeder includes a guide part that guides a carrier tape and is detachably attached to a main body. The guide part includes: a lower member guiding the carrier tape and attached to and detached from the main body; an upper member pressing down the carrier tape from above; a tape introduction part guiding the carrier tape into the upper member at an upstream side thereof in a tape feed direction; a confirmation opening part disposed in the upper member for visually confirming that the carrier tape arrives at a pin engagement range; an open/close mechanism opening and closing the upper member with respect to the lower member; and a positioning mechanism fitting a positioning pin into a feed hole of the carrier tape in the guide part, thereby positioning the carrier tape relative to the guide part in the tape feed direction.

A vacuum roller for a web handling system comprises a hollow, cylindrical, rotably driven drum and an end cap threadingly mounted onto the rear end of the drum. Together, the drum and the end cap define a plurality of individual, externally communicable vacuum paths. A spherical, metal movable element is internally disposed within each vacuum path and regulates the passage of air therethrough. A plurality of magnetic elements is fixedly mounted on a stationary annular holder. In use, each magnetic element selectively displaces each movable element when disposed in close proximity thereto to the extent necessary so as to permit the passage of air through its corresponding vacuum path. As such, the vacuum roller is provided with a predefined range of suction, or vacuum zone, about the outer surface of its rotating drum that directly corresponds to the angular arrangement of the plurality of stationary magnetic elements.

To provide a wire unwinding auxiliary device capable of, compared to a conventional device, effectively preventing an unwound wire material from getting twisted, entangled or flawed. A wire unwinding auxiliary device used for guiding an unwound wire material when unwinding the wire material which is wound in a coiled shape. The device comprises a plurality of rotation members 1a-1e on which the unwound wire material is set to run therethrough, and a non-rotation member 2 provided adjacent to at least a rotation member 1a through which the wire material passes first in the plurality of rotation members 1a-1e, thereby a running path of the wire material is stabilized between the non-rotation member 2 and the rotation member 1a.

A printing device (100,101) has a first print engine (103, 303, 603, 703), a second print engine (105, 305, 605, 705), and a buffer device (107, 307, 609, 709, 711) disposed between the first (103, 303, 603, 703) and second print engines (105, 305, 605, 705). The buffer (107, 307, 609, 709, 711) is configured to store a variable amount of web substrate (106, 301, 713) received from the first print engine (103, 303, 603, 703) and feed the substrate (106, 301, 713) to the second print engine (105, 305, 605, 705).

A media diverter system for directing a media sheet traveling along an input media path into either a first media path or a second media path. One or more roller assemblies are provided including a media-guiding roller having one or more grooves formed around the exterior surface, and an air source for selectively providing an air flow into one or more of the grooves, the air flow being directed between the media sheet and the exterior surface of the media-guiding roller thereby producing a Bernoulli force to draw the media sheet toward the media-guiding roller. A controller selectively activates the air source in at least one of the roller assemblies while the corresponding media-guiding roller rotates around its roller axis to draw the media sheet toward the exterior surface of the media-guiding roller, thereby directing the media sheet into either the first media path or a second media path.

A tape feeder includes a guide part that guides a carrier tape and is detachably attached to a main body. The guide part includes: a lower member guiding the carrier tape and attached to and detached from the main body; an upper member pressing down the carrier tape from above; a tape introduction part guiding the carrier tape into the upper member at an upstream side thereof in a tape feed direction; a confirmation opening part disposed in the upper member for visually confirming that the carrier tape arrives at a pin engagement range; an open/close mechanism opening and closing the upper member with respect to the lower member; and a positioning mechanism fitting a positioning pin into a feed hole of the carrier tape in the guide part, thereby positioning the carrier tape relative to the guide part in the tape feed direction.

A film transport apparatus includes: an edge sensor that detects a lateral position deviation of a film; a lateral position correction device that corrects a lateral position of the film with a guide roll; a tension sensor that detects tensions applied respectively near left and right ends of the film; and a control unit that executes feedback control such that the lateral position correction device is controlled on the basis of the lateral position deviation detected by the edge sensor so that the film is located at a target position. The control unit changes the feedback control based on a left and right tension difference, which is a difference between the tension applied near the left end of the film and the tension applied near the right end of the film, the tensions being detected by the tension sensor.

A printing apparatus includes: a motor which drives a shaft of a roll body around which a medium is wound, in the feeding direction of the medium; a transport roller which transports the medium fed from the roll body; and a control section which supplies electric power for rotating the roll body to the motor, wherein the electric power that the control section supplies to the motor at the time of the start of the feeding of the medium is larger when the diameter of the medium that is wound around the roll body is R2 (

A buffer store for a flat web material includes two roller registers having freely rotatable rollers movable relative to one another in a direction radial to a roller axis, thereby forming loops of the web material between the rollers, a piston-cylinder arrangement having a chamber containing a compressible medium and acting as a spring between the registers to generate web tension in the material, and a control-valve arrangement that switches between a first condition, for normal operation, and a second condition, for operation during a fault. In the first condition, the control-valve arrangement connects the cylinder chamber of the piston-cylinder arrangement to a device for providing a constant operating pressure. In the second condition, the control-valve arrangement closes the cylinder chamber of the piston-cylinder arrangement and connects it to a relief valve that relieves pressure therein to a residual pressure significantly smaller than the operating pressure.

A method of setting web tensioning in a processing machine for processing a material web, in particular in a shaftless printing machine, wherein, for the purpose of setting the web tensioning in a first web-tensioning portion, which is bounded upstream by a first clamping location and downstream by a second clamping location, the first clamping location is given a control command, and at least one clamping location which is located upstream of the first clamping location, as seen over the course of the web tensioning, and at least one clamping location which is located downstream of the second clamping location, as seen over the course of the web tensioning, are precontrolled in dependence on the first control command, where the second clamping location is not adjusted.

In the separation of a cover tape 15e from a carrier tape 15 performed by a cover tape separating mechanism 50, a cover tape 15e, which is separated from a base tape 15a by a separating blade edge 51f, comes into contact with a concave conical surface 52c, so that one side portion of a cover tape 15e is bent toward the other side portion; and the bent cover tape 15e is pressed against a guide surface 32s from below while the carrier tape 15 is guided to a pick-up position. Accordingly, the cover tape 15e is folded on the base tape 15a in a flat shape.

A debris sweep and dry assist device is for use with a strapping machine. The debris sweep and dry assist device is positioned between the strapping machine and an associated strap supply. The device includes a body having a strap inlet and a strap outlet and defining a strap path therethrough. The body has a first wall at about the strap inlet and a second wall at about the strap outlet. The body has a first manifold and a plurality of first branches extending between the first manifold and the first wall to provide a plurality of flow paths from the first manifold to the environs through the first branches. A compressed is gas directed into the first manifold and flows out of the first branches, and is directed onto strap material at a location at about the strap inlet.

A method is disclosed for web tension setting in a processing machine for processing a material web, in particular a shaftless printing press. In order to set the web tension in a first web tension section with a length L which is delimited upstream by a first clamping point and downstream by a second clamping point, the first clamping point is loaded with a first manipulated variable which is produced using a first element with a first transfer function G1(s) (G3), and the second clamping point is loaded with a second manipulated variable which is produced using a second element with a second transfer function G2(s) (G4), wherein c1G1(s)=−c2G2(s). Thus, it is possible to keep the speed constant even during the regulation at a fixed or variable point x within the web tension section, wherein x=|c1/(c1+c2)|L lies behind the first clamping point.

The device (100) is destined to receive flanked continuous strips (1, 2) from an arrival line (L), and feed them towards a transversal cutting station (SR). The device (100) comprises: a basin (3), associated to a terminal part of the arrival line (L), destined to enable formation, in each of the strips (1, 2) of a free loop (A1, A2) in a downwards direction; deviator organs (4), at a 45° angle, provided downstream of the basin (3), destined to guide the strips (1, 2) such as to orientate them perpendicularly to the arrival direction, horizontally centered and correctly staggered in height such as to enter the transversal cutting station (SR).

A flexible and continuous substrates-conveying sheet has a plurality of to be processed substrates disposed on or in it. A nondestructive transferring unit includes a plurality of first transferring rolls and a plurality of second transferring rolls. The first transferring rolls make contact with a first surface of the substrates-conveying sheet where that surface can have electrostatically-induced charge formed thereon. Each of the first transferring rolls includes a first central portion charged with a positive electric charge and a first outer portion surrounding the first central portion. The second transferring rolls make contact with the first surface of the substrates-conveying sheet. The second transferring rolls are disposed alternately with the first transferring rolls. Each of the second transferring rolls includes a second central portion charged with a negative electric charge and a second outer portion surrounding the second central portion.

In a web printer, tension on the moving web is controlled by monitoring the tension on the web between two rollers and selectively operating an actuator driving the second roller to restore the tension to an acceptable range. The operation of the actuator includes modulating the speed at which the second roller is driven.

Groups of phase shifted Pulse Width Modulation signals are generated that maintain their duty-cycle and phase relationships as a function of the period of the PWM signal frequency. The multiphase PWM signals are generated in a ratio-metric fashion so as to greatly simplify and reduce the computational workload for a processor used in a PWM system. The groups of phase shifted PWM signals may also be synchronized with and automatically scaled to match external synchronization signals.

A device for detecting a PWM wave, comprising: a PWM wave generating module, configured to generate the PWM wave; a detecting module coupled to the PWM wave generating module, configured to receive the PWM wave and to determine an electric level of the PWM wave; a timer coupled to the detecting module, configured to start a counting when the detecting module receives the PWM wave, and to interrupt the counting when the counting reaches a predetermined value, the detecting module determining whether the electric level of the PWM wave is a high electric level or a low electric level when the counting is interrupted; and a calculating module coupled to the detecting module, configured to calculate a duty ratio of the PWM wave based on a number of high electric level and a number of low electric level of the PWM wave determined within one period of the PWM wave.

In an embodiment, a method of generating a pulse-width modulated signal from an input signal includes calculating a finite number of basis functions of a first pulse-width modulated signal based on the input signal, and forming an electronic output based on the calculated finite number of basis functions.

A phase-locked loop double-point modulator may include a frequency divider having a ratio which can be changed by a first modulation signal, and an oscillator, a frequency of which can be changed by a second modulation signal correlated to the first modulation signal. A calibration circuit may be configured, in a calibration mode, to match the gains of the first and second modulation signals based on frequency measurements of the oscillator for two different calibration values of the second modulation signal. The phase-locked double-point modulator may also include an attenuator having a constant ratio greater than 1 and placed in the path of the second modulation signal, and a selector switch configured to be controlled by the calibration circuit to reduce the ratio of the attenuator in the calibration mode.

An amplifier receives an amplitude signal of a polar modulated signal at a base terminal of a transistor and receives a phase modulated carrier signal of the polar modulated signal at the base terminal of the transistor. The amplifier combines the amplitude signal and the phase modulated signal to produce a full complex waveform at a collector terminal of the transistor.

Some embodiments relate to a phase shifter that includes an I/Q phase shifter and at least one LC balun. Compared to conventional phase shifters, phase shifter has primarily only LC components, thereby limiting losses relative to conventional solutions. In one embodiment, for example, a phase shifter shows a large bandwidth at 77 GHz center frequency (e.g., 1 dB amplitude error bandwidth is approximately 40 GHz; 1° phase error bandwidth is about 16.5 GHz). The inductors included in phase shifter, in contrast to the quarter wave transmission lines used in conventional phase shifters, reduces chip area compared with conventional solutions. In some embodiments, an emitter follower helps to provide a relatively constant output that is largely independent of temperature, input power, VCC, manufacturing variation, and so on.

A frequency synthesizer for a WLAN transceiver is disclosed that may be used to generate 5.4 GHz and 2.4 GHz signals. The frequency synthesizer may be configured to minimize VCO pulling by using VCO operating frequencies that are not integer multiples of the RF bands. Further, the frequency synthesizer may be configured to minimize interference with other frequency bands used by existing wireless systems.

A modulator generates a baseband digital signal from an information-bearing digital signal. The baseband signal has time-varying phase and amplitude defined by a sequence of complex data words, each having an in-phase (I) component and a quadrature (Q) component. A noise-shaping modulator generates a noise-shaped digital signal from the baseband digital signal such that quantization noise in the noise-shaping modulator is attenuated by a spectral null of its noise transfer function. The spectral null is selected by a noise-shaping parameter corresponding to a selected one of a plurality of output frequencies. A signal converter generates an analog signal conveying the information of the information-bearing digital signal on an analog carrier signal having the selected output frequency.

A signal generator for a transmitter or a receiver for transmitting or receiving RF-signals according to a given communication protocol includes an oscillator and a mismatch compensator. The oscillator is configured to provide a signal generator output signal having a signal generator output frequency and comprises a fine tuning circuit for providing a fine adjustment of the signal generator output frequency based on a fine tuning signal and a coarse tuning circuit for providing a course adjustment of the signal generator output frequency based on a coarse tuning signal. The mismatch compensator is configured to receive the signal generator output signal and compensate a frequency mismatch between a desired signal generator output frequency and the signal generator output frequency generated by the oscillator by providing the fine tuning signal for changing the state of the fine tuning circuit of the oscillator and by providing the coarse tuning signal for changing a state of the coarse tuning circuit of the oscillator. The mismatch compensator provides the coarse tuning signal during a guard period defined in the given communication protocol, during which no RF-signals are transmitted by the transmitter or no RF-signals are to be received by the receiver, such that the state of the coarse tuning circuit is changed within the guard period.

A method for tuning a digital compensation filter within a transmitter includes: obtaining at least one resistance-capacitance (RC) detection result, wherein the digital compensation filter includes an RC compensation module; and tuning the digital compensation filter by inputting the RC detection result into the RC compensation module. For example, the RC detection result may correspond to a detected value representing a product of a resistance value and a capacitance value. In another example, the at least one RC detection result may be obtained by performing RC detection on at least a portion of the transmitter without individually measuring resistance values of resistors therein and capacitance values of capacitors therein. An associated digital compensation filter and an associated calibration circuit are also provided.

A new coded continuous phase modulation (CPM) scheme is proposed to enhance physical layer performance of the current DVB-RCS standard for a satellite communication system. The proposed CPM scheme uses a phase pulse design and combination of modulation parameters to shape the power spectrum of CPM signal in order to improve resilience to adjacent channel interference (ACI). Additionally, it uses a low complexity binary convolutional codes and S-random bit interleaving. Phase response using the proposed CPM scheme is a weighted average of the conventional rectangular and raised-cosine responses and provides optimum response to minimize frame error rate for a given data rate.

A PWM circuit that can have two refresh rates, including: a first PWM signal generator and a second PWM signal generator; wherein the first PWM signal generator and the second PWM signal generator respectively control refresh rates in two dimensions of an output data generated from a target apparatus. A PWM signal generation method that can have two refresh rates, including: generating a first PWM signal; generating a second PWM signal; and controlling refresh rates in different dimensions of an output data generated from a target apparatus respectively by using the first PWM signal and the second PWM signal.

Techniques and mechanisms for configuring logic to implement a signal modulation. In an embodiment, the logic includes a finite impulse response (FIR) module comprising circuitry. The selection circuitry may be operable to concurrently receive signals from latch circuitry of the FIR module and, based on the signals, to select an input group of the selection circuitry and to output a voltage identifier. In another embodiment, configuration logic is operable to set an operational mode which determines a total number of concurrent input signals, received by the FIR module, which the FIR module will use to select an input group for generating an output representing a voltage level.

A time-varying formant is generated at a formant frequency by generating first and second harmonic phase signals having first and second harmonic numbers, respectively, in relation to a modulation frequency. The first and second harmonic phase signals are generated in proportion to a master phase signal, which varies at the modulation frequency, modulo a factor corresponding to their harmonic numbers. First and second sound signals, based on the first and second harmonic phase signals, are frequency modulated to create an arbitrarily rich harmonic spectrum, depending on an FM index. The time-varying formant is generated by generating a time-varying combination of the first and second harmonic sound signals, weighting the first and second harmonic sound signals in accordance with their spectral proximities to the formant frequency. One or more of the harmonic numbers are updated when the time-varying formant frequency passes the frequency of either sound signal.

A method for generating/transmitting a transmission-unit symbol sequence is disclosed. In the case of transmission information, the information is modulated in time and frequency domains on the basis of a predetermined transmission unit (e.g., a transmission time interval TTI or slot), simultaneous transmission of the information is made, and then a transmission unit symbol is generated/transmitted. A transmission sequence is masked in each symbol contained in one transmission unit. Symbol-unit circular shift (cyclic shift) is applied to the masked result, so that transmission efficiency increases. A control signal transmission method for supporting a variety of formats and a signal transmission method based on a prime-length sequence are also provided.

A communications transmitter includes a baseband processor configured to generate amplitude, angle, in-phase and quadrature baseband signals and a combination modulator that is configurable to modulate in the polar domain and, alternatively, in the quadrature domain. The combination modulator includes a quadrature modulator and a separate and distinct angle modulator that is configured to serve as a local oscillator for the quadrature modulator. In one embodiment of the invention the combination modulator is configured to modulate in the quadrature domain when the transmitter is operating according to a first communications condition (e.g., first transmit power level or first modulation scheme) and is configured to modulate in the polar domain when the transmitter is operating according to a second communications condition (e.g., second transmit power level or second modulation scheme).

A device for mixing multiple (N) pulse density modulated (PDM) bit streams of a bit rate, the device comprises an input logic, an error accumulation circuit, an error correction circuit and an adder of more than N bits; wherein the device is arranged to output an output PDM bit stream that represents a mixture of the multiple input PDM bit streams; wherein the output PDM bit stream comprises a plurality of output PDM bits, wherein a certain output PDM bit of a plurality of output PDM bits that form the output PDM bit stream is generated during a certain clock cycle; wherein the input logic is arranged to select, during each fraction of the certain clock cycle, a current bit of a selected PDM bit stream, wherein different PDM bit streams are selected during different fragments of the certain clock cycle; wherein the error accumulation circuit is arranged to store intermediate values during a first fraction till a penultimate fraction of the certain clock signal and to store a last value during a last fraction of the certain clock signal.

A frequency modulating path for generating a frequency modulated clock includes a direct feed input arranged for directly modulating frequency of an oscillator, and a compensating feed input arranged for compensating effects of frequency modulating on a phase error; wherein the compensating feed input is resampled by a down-divided clock that is an integer edge division of the oscillator. A reference phase generator for generating a reference phase output includes a resampling circuit, an accumulator and a sampler. The resampling circuit is for resampling a modulating frequency command word (FCW) input to produce a plurality of samples. The accumulator is for accumulating the samples to generate an accumulated result. The sampler is for sampling the accumulated result according to a frequency reference clock, and accordingly generating a sampled result, wherein the reference phase output is updated according to at least the sampled result.

Provided is a method for transmitting data in a communication or broadcasting system using a linear block code by generating a codeword by encoding input information data bits, interleaving the codeword; outputting modulation signal-constituting bits by bit-mapping the interleaved codeword using a bit-mapping table predetermined depending on a modulation scheme and a coding rate, outputting a modulation signal by modulating the modulation signal-constituting bits and transmitting the modulation signal via a transmit antenna.

A frequency modulator includes a digitally-controlled oscillator (DCO) arranged for producing a frequency deviation in response to a modulation tuning word and a phase-locked loop (PLL) tuning word. In addition, another frequency modulator includes a DCO and a DCO interface circuit. The DCO is arranged for producing a frequency deviation in response to an integer tuning word and a fractional tuning word. The DCO interface circuit is arranged for generating the integer tuning word and the fractional tuning word to the DCO, wherein the fractional tuning word is obtained through asynchronous sampling of a fixed-point tuning word.

Embodiments of digital high-speed bi-phase modulator and method for bi-phase modulation are generally described herein. In some embodiments, the digital high-speed bi-phase modulator comprises a high-speed digital divider, a high-speed digital multiplexer, and matched signal paths provided between the divider and the multiplexer. The high-speed digital divider is configured to receive a carrier signal and generate complementary output signals. The high-speed digital multiplexer is configured to switch between the complementary output signals and generate a bi-phase modulated output at a carrier frequency (fc) modulated with a bi-phase code. The bi-phase code may be provided to control inputs of the multiplexer.

A radio frequency generator includes a power control module, a frequency control module and a pulse generating module. The power control module is configured to generate a power signal indicating power levels for target states of a power amplifier. The frequency control module is configured to generate a frequency signal indicating frequencies for the target states of the power amplifier. The pulse generating module is configured to (i) supply an output signal to the power amplifier, (ii) recall at least one of a latest power level or a latest frequency for one of the target states of the power amplifier, and (iii) adjust a current power level and a current frequency of the output signal from a first state to a second state based on the power signal, the frequency signal, and at least one of the latest power level and the latest frequency of the power amplifier.

Provided is a method of generating a driving signal for driving a dual mode supply modulator for a power amplifier. The method includes obtaining an envelope of a complex baseband signal to be transmitted, comparing the envelope of the complex signal with a preset threshold value, when a current envelope of the complex signal is the preset threshold value or greater or when there is a result having the preset threshold value or greater in previous N comparisons, outputting a digital board output signal configured with a first logic level through a digital-to-analog converter; and when the current envelope of the complex signal is smaller than the preset threshold value and when there is no result having the preset threshold value or greater in the previous N comparisons, outputting a digital board output signal configured with a second logic level through the digital-to-analog converter.

An apparatus for coding a signal by means of amplitude shift keying comprises a class E amplifier including a switching transistor, to whose gate is supplied a voltage having an operating frequency for operating the class E amplifier. For achieving an amplitude shift keying in the output signal of the class E amplifier, a circuit for switching the operating frequency of the voltage supplied to the gate of the switching transistor, or the resonance frequency of the class E amplifier, between a first value and a second value is provided and in order to switch a deviation degree between the operating frequency and the resonance frequency between a first value and a second value.

In an embodiment, a method of producing a multi-level RF signal includes producing plurality of pulse-width modulated signals based on an input signal. The method further includes driving a corresponding plurality of parallel amplifiers with the plurality of pulse-width modulated signals by setting a parallel amplifier to have a first output impedance when a corresponding pulse-width modulated signal is in an active state and setting the parallel amplifier to have a second output impedance when the corresponding pulse-width is in an inactive state. The method also includes phase shifting the outputs of the plurality of parallel amplifiers, wherein phase shifting transforms the second output impedance into a third impedance that is higher than the second output impedance, and combining the phase shifted outputs.

A transmission device for transmitting a signal in a wireless communication system is provided. The transmission device includes: a serial-to-parallel converter configured to convert an input serial bit stream into a parallel bit stream having three bits; and a phase rotation symbol mapper configured to map the parallel bit stream to a symbol having phase rotation characteristics, wherein when the parallel bit stream includes first to third bits, the phase rotation symbol mapper maps the second and third bits to a complex variable and sequentially maps a real number part and an imaginary number part of the complex variable to the front part and the rear part of a symbol in this order or to the rear part and the front part of the symbol in this order.

According to some embodiments, a method and apparatus are provided to vary a clock signal frequency for a first time period between a lower limit of a range of problematic frequencies and a frequency lower than the lower limit, and vary the clock signal frequency for a second period of time between an upper limit of the range of problematic frequencies and a frequency greater than the upper limit.

A modulation apparatus for a class D switching amplifier is capable of reducing power consumption of an Electro-Migration Interface (EMI) of an output end and a gate driver end in a zero input signal. The modulation apparatus for a class D switching amplifier includes a control unit for detecting and outputting a control signal which is a common signal component of a first modulation signal modulated by using a first input signal and a second modulation signal modulated by using a second input signal; and is characterized by feedback of a first output signal, a second output signal and a common output signal outputted by using the first modulation signal, the second modulation signal and the control signal through an input of the modulation apparatus.

In a method of transmitting a data stream from a transmitter in a multiple-input-multiple-output (MIMO) wireless communication system, where the transmitter comprises a plurality of transmit antennas, a discrete Fourier transform (DFT) is applied to the data stream to generate a plurality of symbol sequences; symbols of a first symbol sequence from the plurality of symbol sequences are paired with symbols of a second symbol sequence from the plurality of symbol sequences to generate a plurality of symbol pairs, wherein the pairing results in an orphan symbol; a space-time block code (STBC) is applied to the symbol pairs to generate a plurality of sets of STBC symbols, each set of STBC symbols being associated with a corresponding one of the plurality of antennas; a cyclic delay diversity (CDD) operation is applied to the orphan symbol to generate a plurality of CDD symbols, each CDD symbol being associated with a corresponding one of the plurality of antennas; and each one of the antennas transmits the corresponding set of STBC symbols and the corresponding CDD symbol.

In various embodiments, systems and methods for generating high-precision pulse-width modulation include a delay-locked loop comprising multiple delay units having time-variable delays, control logic for selecting a subset S of the multiple delay units to thereby generate a time-invariant shift amount having a precision finer than that of a system clock and circuitry for applying the shift amount to rising and falling edges of a pulse-width modulation waveform to thereby generate a high-precision pulse-width modulation waveform.

An ultra-wide band frequency modulator is disclosed. The frequency modulator includes a direct modulation phase lock loop that receives a small component. The frequency modulator also includes a delay module that produces a plurality of delay lines. The frequency modulator further includes an edge selector that receives a large component and the plurality of delay lines.