44results about How to "Constant bandwidth" patented technology

Aspects of the present invention relate to providing see-through computer display optics and reduction of color breakup in presented content.

Aspects of the present invention relate to providing see-through computer display optics and reduction of color breakup in presented content.

Aspects of the present invention relate to providing see-through computer display optics and reduction of color breakup in presented content.

The present invention facilitates clock and data recovery (330,716 / 718) for serial data streams (317,715) by providing a mechanism that can be employed to maintain a fixed tracking capability of an interpolator based CDR circuit (300,700) at multiple data rates (e.g., 800). The present invention further provides a wide data rate range CDR circuit (300,700), yet uses an interpolator design optimized for a fixed frequency. The invention employs a rate programmable divider circuit (606,656,706) that operates over a wide range of clock and data rates (e.g., 800) to provide various phase correction step sizes (e.g., 800) at a fixed VCO clock frequency. The divider (606,656,706) and a finite state machine (FSM) (612,662,712) of the exemplary CDR circuit (600,650,700) are manually programmed based on the data rate (614,667). Alternately, the data rate may be detected from a recovered serial data stream (718) during CDR operations (on-the-fly) utilizing a frequency detection circuit (725) to automatically program the divider (706) and FSM (712) to provide CDR circuit operation at the nearest base clock rate (716).

A method and apparatus for bandwidth reservation for data flows in interconnection networks. Some embodiments of an apparatus for transmitting a data stream include a transmitter to transmit a data stream to a recipient apparatus, the data stream including a plurality of data packets. The apparatus further includes a receiver to receive a response from the recipient apparatus regarding data packet arrival status, and a network unit to direct the operation of the transmitter, the network unit to direct the transmitter to maintain the data stream with a constant bandwidth.

The invention discloses a wireless sensor network application-oriented low-power consumption radio frequency receiving and sending device which comprises a duplexer, a radio frequency front end, a variable gain complex filter, an automatic frequency tuning circuit, a programmable gain amplifier, a phase-locked loop frequency synthesizer, a digital processor, a storage, a variable gain power amplifier, a mixer and a low pass filter, wherein the duplexer, the radio frequency front end, the variable gain complex filter, the automatic frequency tuning circuit and the programmable gain amplifier form a receiving link which is used for receiving and processing a radio frequency signal and converting the radio frequency signal into a low-medium frequency digital signal so that the signal can be conveniently processed by a subsequent analog-digital converter later; the duplexer, the variable gain power amplifier, the mixer and the low pass filter form an emitting link which is used for mixing a baseband analog modulation signal into a carrier frequency and sending a wireless signal; and the receiving link and the emitting link share the duplexer. The wireless sensor network application-oriented low-power consumption radio frequency receiving and sending device realizes singlechip integration by adopting a standard CMOS (Complementary Metal Oxide Semiconductor) process, is simple in structure and low in power consumption, and is applicable to a wireless sensor network.

The present invention provides a radar altimeter system with a closed loop modulation for generating more accurate radar altimeter values. The system includes an antenna, a circulator, a receiver, and a transmitter. The circulator receives or sends a radar signal from / to the antenna. The receiver receives the received radar signal via the circulator. The transmitter generates a radar signal and includes a phase-locked loop circuit for generating the radar signal based on a pre-defined phase signal. The transmitter includes a direct digital synthesizer that generates the phase signal based on a pre-defined clock signal and a control signal. The system includes a digital signal processor and a tail strike warning processor that determine position of a tail of the aircraft relative to ground and present an alert if a warning condition exists based on the determined position of the tail of the aircraft and a predefined threshold.

In one embodiment, a set of tracking filters to be coupled between an amplifier and a mixer is provided. The tracking filters may be differently configured depending on band of operation. For example, a first set of the filters can be configured to maintain a substantially constant Q value across their operating bandwidth while a second set of the filters can be configured to maintain a substantially constant bandwidth across their operating bandwidth.

The invention discloses a radar detection and communication transmission method based on piecewise linear frequency modulation signals to solve the problems that the radar detection performance is reduced after radar signals modulate communication data and that shared signals are not conducive to linear amplification. The method includes the following concrete steps: pre-processing radar communication data; setting piecewise linear frequency modulation signal parameters; generating piecewise linear frequency modulation signals; emitting and receiving pulse modulation signals; detecting the distance and speed of a radar target; demodulating the radar communication data. Piecewise linear frequency modulation signals with a constant envelope and a fixed bandwidth are designed, and data modulation is performed on the time width and frequency modulation polarity of intermediate linear frequency modulation signals to make the signals carry communication information, so that the signals become shared signals that can detect a target and transmit data. The method overcomes the problem of range ambiguity existing in detection by common pulse signals, solves the contradiction between communication transmission and power occupation by radar detection, and is more accurate in transmission and lower in error rate. The method is applied to an integrated radar communication system.

A tunable inductor arrangement arrangable on a chip or substrate is disclosed. The tunable inductor comprises a first winding part connected at one end to a first input of the tunable inductor arrangement, a second winding part connected at one end to the other end of the first winding part, a third winding part connected at one end to a second input of the tunable inductor arrangement, a fourth winding part connected at one end to the other end of the third winding part, and a switch arrangement arranged to tune the tunable inductor arrangement. Tuning is performed by selectively provide any of a circuit comprising the first and third winding parts in series between the first and second inputs, or a circuit comprising the first, second, fourth and third winding parts in series between the first and second inputs. The first and third winding parts are arranged on the chip or substrate such that magnetic fields of the first and third windings are essentially common, and the second and fourth winding parts are arranged to cancel electro-magnetic coupling with the first and third winding parts. A receiver, a transceiver, a communication device, a method and a computer program are also disclosed.

The invention discloses a complementary digital variable gain amplifier. The variable gain amplifier comprises a transconductance amplifier and a transimpedance amplifier. The transconductance amplifier is formed by connecting four transconductance stages of the same structure in parallel and used for converting input voltage into output current, and controls over the equivalent transconductance value of the transconductance stage and the gain of the variable gain amplifier is achieved by controlling the stage number of the accessed transconductance stage. And the transimpedance amplifier is used for converting the output current obtained by the transconductance amplifier into the output voltage of the transimpedance amplifier. The transimpedance amplifier comprises a first transimpedanceamplifier (A1), a first resistor (R1) and a second resistor (R2). The step length and gain adjustable range of the variable gain amplifier are determined through selection of the transconductance value of each transconductance stage and selection of the number of the transconductance stages, and control over the transconductance value of the transconductance stage amplifier is achieved. Half current can be saved under the same gain requirement, and power consumption can be reduced when the same equivalent gain is achieved.

The invention discloses a broad tuning coaxial electrically tunable filter and a debugging method thereof, and relates to the technical field of microwave communication. The electrically tunable filter comprises a driving circuit, a stepping motor, a transmission mechanism and a filter part, wherein the filter part is provided with two coupling seats, a plurality of resonant cavities and a plurality of intercavity coupling structures; the coupling seats are fixedly equipped with trapezoidal coupling loops; adjustable frequency compensation devices are arranged on outer conductors of the resonant cavities; the intercavity coupling structures are metal plates with two or more circular holes or polygonal holes. The debugging method can allow the electrically tunable filter to reach a tuning range above an octave and have constant band width, stable amplitude frequency and echoing characteristics, improves product debugging efficiency and lowers manufacture and debugging costs.

A flying machine or other vehicle includes at least two antenna units and a central control unit. In a first mode of operation, the two antenna units send and / or receive signals independent of each other in different, non-overlapping frequency bands. The central control unit is adapted to control the two antenna units in a second mode of operation such that the two antennas transmit and / or receive a common signal in a common frequency band using a Multiple Input Multiple Output transmission technique.

The invention relates to a coaxial cavity tunable filter with balanced bandwidth at a high end and a low end. The prior coaxial cavity tunable filter can not keep the constant bandwidth in the workingfrequency band at different frequencies. The coaxial cavity tunable filter with balanced bandwidth at the high end and the low end comprises a filter shell, wherein the filter shell is divided into aplurality of coaxial cavities by baffle plates which are provided with rectangular coupling windows; the center of the bottom in each coaxial cavity is provided with a cylindrical inner conductor; aninput coaxial joint and an output coaxial joint are respectively arranged on the two opposite side walls of the filter shell; one end of a coupling loop is connected with the coaxial joints, and theother end of the coupling loop is connected with the bottom in each cavity of the filter shell; the coupling loop among the cavities is in a solenoid type structure; and two ends of a spiral wire arerespectively positioned in two adjacent coaxial cavities, and a leading wire is led out and is connected with the bottom of the filter shell. In the invention, the filter coupling windows and the solenoid type coupling loop among the cavities are combined, and by using the structure, the bandwidth of the filter can be kept constant in the whole frequency tuning range, and the insertion loss and the ripples of the filter are greatly improved.

The invention provides a small helical antenna, which relates to an antenna, and solves the problem of large volume of the existing helical antenna. The small helical antenna is formed by the winding of a helical wire; one end of the helical wire is connected with one end of an impedance transformer; the number of helical turns of the helical antenna is at least one; the helical climbing angle ofthe helical antenna is from 5 degrees to 20 degrees. The invention is suitable for satellites, airships, ballistic rockets, and the like and is applied to emitting or receiving circular polarization electromagnetic wave signals.

The invention provides a programmable complex filter, a GNSS system chip and a radio frequency receiver. The programmable complex filter supports a zero intermediate frequency mode and a low intermediate frequency mode. The programmable complex filter comprises a trans-impedance amplifier module, a complex filter module and an RC calibration module. The trans-impedance amplifier module converts the intermediate frequency differential current signal into a noise intermediate frequency differential voltage signal; The complex filter module is used for filtering interference signals in the noise intermediate frequency differential voltage signals, so that the intermediate frequency differential voltage signals can be output in a zero intermediate frequency mode or a low intermediate frequency mode; the RC calibration module comprises an analog processing unit and a digital processing unit and is used for controlling the switching state of the resistance-capacitance array unit according to the switching signal and the clock signal; when the switch state is closed, the programmable complex filter supports a low-intermediate frequency mode; when the switch state is off, the programmable complex filter supports a zero intermediate frequency mode. The invention has the characteristics of high integration level and flexible and configurable mode.

The invention discloses a constant-bandwidth broadband filter with an electrically-adjusted transmission zero point. The constant-bandwidth broadband filter comprises a micro-strip dielectric substrate (1), a metal grounding plate (2), a short-circuit branch loading resonator (3), a coupling feeder line (4), a grounding hole (5), a capacitance variable diode (6) and a DC biasing circuit (7). A folded short-circuit branch loading resonator is adopted to increase a current path, the resonance frequency is reduced, and a folding double-feeder structure is loaded on the inner side, so that the broadband filter is compact in structure and small in size. A capacitance variable diode control source is coupled with a load, and the capacitance value of the capacitance variable diode is adjusted through a direct current bias circuit, so that the position and the quantity of transmission zero points are changed, and the selective performance of the broadband filter is improved. The performance ofthe passband is not affected, and the constant bandwidth is kept, so that the performance stability of the filter is ensured.

The embodiment of the invention discloses a high-energy-efficiency equalizer architecture. The architecture comprises a filtering module which is used for filtering an input signal, a processing module which is connected with the filtering module, the processing module comprises a plurality of MOS tubes which are in complementary connection, and the processing module is used for transconductance amplification of a current signal of the input signal; and the architecture further comprises a conversion module which is connected with the processing module, and the conversion module is used for converting the current signal into a voltage signal. According to the high-energy-efficiency equalizer architecture provided by the embodiment of the invention, by accessing a complementary transconductance tube and using the same transconductance amplification stage current, double transconductance can be obtained, and meanwhile, the output transresistance stage can still keep constant bandwidth and gain, so that compared with a traditional linear equalizer architecture, the high-energy-efficiency equalizer architecture achieves the effects of high compensation capability and high driving capability.

The invention discloses a folding cavity dielectric loading adjustable filter, which comprises a group of resonant cavities and a tuning mechanism, wherein the resonant cavities are coplanar on the top surface and the bottom surface respectively, and the resonant cavities are arranged in a non-linear staggered manner, and coupling windows are respectively arranged between each resonant cavity andits upper and lower resonant cavities. At least two through holes are formed on the top surface / bottom surface of each resonant cavity. The tuning mechanism comprises a mounting disk arranged in parallel with the top and bottom surfaces of the resonant cavity, A set of tuning dielectric rods with the same height and corresponding to the through holes are vertically mounted on the mounting disk, and each tuning dielectric rod can be extended into the corresponding resonant cavity through the corresponding through holes with the relative movement between the mounting disk and the resonant cavityat the same depth. The invention also discloses a folding cavity medium loading adjustable duplexer. The invention has the advantages of compact structure, precise frequency tuning, basically keepingthe bandwidth unchanged while tuning the frequency, low echo and no microwave signal leakage.

The invention discloses a digital control variable gain amplifier, which comprises three stages of VGA circuits and an output buffer circuit. The first stage and the second stage of the three stages of VGA circuits are composed of a variable transconductance amplifier and a constant trans-impedance amplifier. The third stage is composed of a variable transconductance amplifier and a variable trans-impedance amplifier, a high-pass filter is adopted between the two stages of VGA circuits to eliminate direct-current bias voltage generated by each VGA unit, the reliability of the circuits is guaranteed, and an output buffer is used for driving 100-ohm differential load impedance. The variable transconductance stage and the variable transimpedance stage are introduced into the three stages of VGA circuits at the same time, so that the problem of mismatching caused by excessive transistors is avoided, high gain, accurate gain step length and constant bandwidth are realized, the linearity isrelatively good, and a wide dynamic range system is realized.

The invention discloses a multi-transimpedance constant-bandwidth ultralow-noise TIA, belongs to the technical field of optical communication chips, and aims to solve the problems that the sensitivityand the linearity of an output signal are influenced and the overall performance of the TIA cannot be ensured due to large bandwidth and noise change of a common selectable transimpedance TIA. A capacitor C1 is connected to the two ends of a trans-resistor RF1 in parallel, a capacitor C2 is connected to the two ends of a trans-resistor RF2 in parallel, and the sizes of the capacitor C1 and the capacitor C2 are adjusted to meet the requirement that the TIA bandwidth is constant before and after a switch S1 is closed. The two ends of the trans-resistor RF1 are further connected with a circuit structure in parallel. A resistor R3 and a capacitor C5 are connected in series and then connected to the two ends of a capacitor C4 in parallel and then connected with a resistor R2 in series and thenconnected to the two ends of the trans-resistor RF1 in parallel. The two ends of the trans-resistor RF2 are further connected with a circuit structure in parallel. A capacitor C3 and a resistor R1 are connected in series and then connected to the two ends of the trans-resistor RF2 in parallel. The TIA bandwidth is constant before and after the switch S1 is closed by adjusting the capacitors C1-C5.

The invention provides a filter. The filter comprises a filter cavity, at least one partition plate and resonant rods, wherein the partition plate is arranged in the filter cavity and is parallel to a side wall of the filter cavity, the filter cavity is partitioned to a plurality of resonant cavities, the resonant rod is arranged in each resonant cavity, the resonant rods are parallel to the partition plate, and coupling windows are formed in two ends of the partition plate and are used for achieving cavity coupling of the filter. In the filter, a coupling adjustment device is not needed to be additionally arranged, and the filter is simple in structure.

The invention discloses a phase-locked loop frequency synthesizer. The phase-locked loop frequency synthesizer comprises a phase frequency detector, a charge pump and an adaptive filter, a Voltage-controlled oscillator, a Frequency divider and a decoder; the phase frequency detector , a charge pump and an adaptive filter, the Voltage-controlled oscillator, the frequency dividers are sequentially connected in series to form a feedback loop; the decoder is connected between the frequency divider and the self-adaptive filter; the decoder is used for decoding the frequency division ratio of the frequency divider and providing a corresponding control signal for the adaptive filter; and the self-adaptive filter comprises a self-adaptive on-resistance network which has different resistance valuesunder the control of the control signal and can keep the loop bandwidth of the phase-locked loop frequency synthesizer constant. The phase-locked loop frequency synthesizer disclosed by the inventionrealizes that the bandwidth of the loop is not changed along with the change of the output frequency, and has better system stability and response speed.

The invention relates to a design method of a field-weakening controller for an induction motor based on a simplified voltage loop structure, which belongs to the technical field of motor control. The invention solves the problems that the parameter selection of the field-weakening controller based on the voltage closed loop is limited to the trial and error method, and that improper selection of the field-weakening controller parameters will cause system oscillation or even instability. The present invention first resets the voltage setting and voltage feedback, and secondly, according to the output voltage instruction u of the current regulator sq * and u sd * The signal of the voltage closed-loop based field weakening control system is obtained from the control structure of the voltage closed loop I and the voltage closed loop II, and the obtained control structure of the voltage closed loop I and the voltage closed loop II is simplified; finally, the field weakening controller is designed For the PI structure, the system response is corrected by the low-frequency band correction principle. The invention can be applied to the design of the field weakening controller of the induction motor.

The invention relates to a design method for a weak magnetic controller of an induction motor based on simplification of a voltage loop structure, belongs to the technical field of motor control, andsolves the problems that parameter selection of the voltage closed loop based weak magnetic controller is limited to a trial and error procedure and improper parameter selection may cause oscillationeven instability of the system. According to the method, voltage giving and voltage feedback are reset; a control structure of first and second voltage closed loops is selected from a voltage closed loop based weak magnetic control system structure according to signals influencing output voltage instructions usq* and usd* of a current regulator, and the control structure of the first and second voltage closed loops is simplified; and the weak magnetic controller is set as a PI structure, and system response is corrected via a low band correction principal. The method can be applied to design of the weak magnetic controller of the induction motor.