140 results about "Multi-frequency signaling" patented technology

Disclosed herein is a pointer detection apparatus, including: a conductor pattern including a plurality of first conductors disposed in a first direction and a plurality of second conductors disposed in a second direction; a multi-frequency signal production circuit configured to produce a plurality of signals of different frequencies; a first conductor selection circuit configured to selectively supply the signals of different frequencies to those first conductors, between which N ones of the first conductors are interposed, N being a predetermined integer equal to or greater than 0; a second conductor selection circuit configured to selectively receive detection signals from the second conductors; and a signal detection circuit configured to obtain signals of individual frequencies, corresponding to the signals of different frequencies produced by the multi-frequency signal production circuit, which are representative of coupling states at cross points between the first conductors and the second conductors and are received from said second conductor selection circuit.

A method and system is disclosed for reducing multi-frequency signal interference in a wireless communication network. An available frequency spectrum is divided into a plurality of channels, a first wireless communication coverage unit is then segregated into a first number of geographical segments. After the segregated channels are grouped into a second number of channel blocks, each channel block is assigned to at least one of the segregated geographical segments with predetermined priorities. All the above steps are repeated for each neighboring wireless communication coverage unit of the first wireless communication coverage unit, wherein the channels in different channel blocks exhibit no higher mutual interference than the channels in the same channel block, and wherein the channel block assigned for each segregated segment of the first wireless communication coverage unit is different from the channel block assigned for the segregated segment of a second wireless communication coverage unit that immediately borders with the segregated segment of the first wireless coverage unit even if the first and second wireless communication coverage units share the same frequency spectrum.

A method and an apparatus relating to an OFDM data communications system where the sub-carriers are modulated using differential quadrature phase-shift keying (DQPSK). The multi-carrier transmitted signal is directly generated by means of summation of pre-computed sample points. As part of the multi-carrier signal generation, a signal for the guard interval is established. In an acoustic application of this approach, direct radiation of the sub-carrier approach is facilitated. Symbol synchronization in the receiver is based on signal correlation with the missed sub-carrier. Separation of the sub-carriers in the receiver by means of correlation of the received signal and reference signals that are derived from a table of pre-computed values. Optimal non-coherent processing of the sub-carriers without any phase tracking procedures is achieved.

Disclosed herein is a pointer detection apparatus, including: a conductor pattern including a plurality of first conductors disposed in a first direction and a plurality of second conductors disposed in a second direction; a multi-frequency signal production circuit configured to produce a plurality of signals of different frequencies; a first conductor selection circuit configured to selectively supply the signals of different frequencies to those first conductors, between which N ones of the first conductors are interposed, N being a predetermined integer equal to or greater than 0; a second conductor selection circuit configured to selectively receive detection signals from the second conductors; and a signal detection circuit configured to obtain signals of individual frequencies, corresponding to the signals of different frequencies produced by the multi-frequency signal production circuit, which are representative of coupling states at cross points between the first conductors and the second conductors and are received from said second conductor selection circuit.

Methods and apparatus provide for positioning of a rover antenna from GNSS data derived from multi-frequency signals and correction data derived from a network of reference stations. At each of a plurality of epochs, the GNSS data and correction data are used to estimate values defining a rover antenna position and a set of multi-frequency ambiguities. An ionospheric-free carrier-phase ambiguity per satellite is estimated based on a known rover antenna position. The estimated ionospheric-free carrier-phase ambiguity is combined with an estimated widelane ambiguity and with an estimated ionospheric-free ambiguity and with values defining the known rover antenna position to obtain values defining an aided rover antenna position and aided multi-frequency ambiguities.

A tunable top-pole passive notch circuit for attenuating select frequencies of a multi-frequency CATV signal. The circuit includes an input for receiving a multi-frequency CATV signal, and an output for transmitting a portion of the multi-frequency CATV signal, A filter network for attenuating a band of frequencies from the multi-frequency signal is distributed been the input and the output. The filter network includes three parallel branches A, B, and C, each being arranged in series connection between the input and the output. Branch A includes an inductor. Branch B includes an adjustable parallel tank circuit Branch C includes a second adjustable electrical resonator. The filter has frequency response characteristics that are more stable than prior art two-pole notch filters, and similar to the response characteristics of more complex three pole or four pole notch filters. The two-pole tunable notch filter circuit provides a passband response to 1 GHz.

A miniature multi-frequency antenna, comprising at least one dielectric substrate, at least one signal electrode and at least one ground electrode. The signal electrode and the ground electrode are disposed on a substrate. The signal electrode contains at least two branches and at least one branch is partially overlapped with the ground electrode. Each interlayer region between the partially overlapped electrodes forms a specific capacitance. By utilizing this interlayer capacitive effect, the resonant frequency of lower frequency band is achieved while the size of the antenna is effectively reduced. For obtaining the resonant frequency of the high frequency bands, the design concept of PIFA is applied on other branches of the signal electrode. A miniature antenna thus obtained is capable of transmitting/receiving multi-frequency signals having the benefits of easily adjusting impedance and resonant frequency.

The invention provides a long-distance distributed type large-measuring-range rapid response optical fiber dynamic strain sensing device. The device comprises a phase modulator, a multi-frequency signal generating module, an intensity modulator, a microwave switch, an electric pulse generating module, a microwave signal generating module and other components. The signal generating module comprising multi-frequency components is used for modulating the phase of detection continuous light, so that multi-light-frequency components are generated in the detection continuous light, and corresponding Brillouin gain spectrum amplitudes are adjusted through controlling the amplitudes of all the light-frequency components in the detection continuous light. A Brillouin gain spectrum of a needed spectrum width and a spectrum type is obtained through splicing, and the dynamic strain measuring range is greatly enlarged under the condition that the signal-to-noise ratio and the response speed of a system are not destroyed. The frequency difference between two light beams generating a Brillouin amplification effect is fixed in the middle of a beveled edge linear region of the spliced Brillouin gain spectrum, drifting of the spliced Brillouin gain spectrum is converted into power fluctuation of the detection light, and long-distance distributed type large-measuring-range high response speed quantitative measuring on optical fiber dynamic strain and optical fiber static strain is achieved.

The invention provides an antenna system and a mobile terminal. A first metal frame of the antenna system is connected with a metal floor through connection bar positions; a first slot is formed between the first metal frame and the metal floor; one end of a second metal frame is connected with the metal floor; the second metal frame is extended parallel to the lateral side of the metal floor; a second slot is formed between the second metal frame and the metal floor; the end of the first metal frame faces the end of the second metal frame; a slot for providing coupling excitation is arrangedbetween the opposing ends of the first and second metal frames. A radio frequency signal source is electrically connected with the first metal frame or the second metal frame through a matching network so as to form a multi-frequency antenna. The antenna system herein can provide multi-frequency signal communication through one antenna, antenna layout area is saved, antenna design cost is reduced,and implementation of a light and thin body of the mobile terminal is benefited.

The invention discloses a method and a device for detecting the thickness of a multi-layer conductive coating through a vortex. The device comprises a multi-frequency sine excitation signal generation module, a probe, a hall sensor, a filtering and amplifying module, a multi-frequency signal separation module, a signal collection module, an operation module and a display module, wherein the device is used for detecting the thickness of the multi-layer conductive coating through four steps. The method and the device are capable of detecting the thickness of the multi-layer conductive coating; the detection device is simple and excellent in portability; an inverse algorithm is simple and clear in process and easy to implement; the device is high in detection precision.

An apparatus and method of maintaining stability in a servo loop of a disc drive is provided. A dither signal (a single frequency sine wave or a multi-frequency signal) is injected into the servo loop. A servo loop gain error signal is obtained in response to the injected dither signal. A gain of the servo loop is adjusted as a function of the servo loop gain error signal in real-time.

The invention relates to a measuring device and a measuring method of human body impedance. The measuring device consists of a multi-frequency signal generation circuit, a constant-current switching circuit, a multi-way switch, electrodes, a standard resistor, a differential amplifier circuit, a signal acquisition circuit, an ARM controller and a display screen. The measuring device adopts six electrodes combined with the multi-way switch to form five measuring circuits and uses a touch screen to replace a computer for selecting a measuring mode and displaying the measuring result; the multi-frequency signal generation circuit generates multi-frequency excitation signals and can measure five segments of impedance of a human body at different frequencies; and the ARM controller runs an operating system and an application program to control each functional unit to run correctly so as to achieve multi-frequency and multi-segment measurements of the human body impedance. The measuring device has simple design of hardware, is easy to operate, is portable, and has low cost and good market prospect.

The invention discloses a wearable electrical impedance tomography gastric motility information extracting device. The wearable electrical impedance tomography gastric motility information extracting device comprises an electrode array belt, a switch array, an impedance signal measurement module, a DSP and a wireless data transmission module. The electrode array belt is composed of a pasting strip and electrode buckles distributed on the belt at equal intervals and is connected with the switch array through a wire. The switch array is composed of an excitation gating switch and a measurement gating switch. An excitation current source is composed of a DDS multi-frequency signal generation unit and a voltage and current conversion module, and excitation current is injected in a corresponding electrode pair of the electrode array belt through the excitation gating switch. The impedance signal measurement module is composed of an instrumentation amplifier, a programmable amplifier, a demodulator and an AD conversion module. The measurement gating switch picks up impedance signals of the corresponding electrode pair on the electrode array belt and converts the impedance signals into digital information, and the DSP uploads the generated digital information to a portable intelligent device through the wireless data transmission module for processing.

The invention provides a multi-qubit regulation reading device, comprising a double conversion control unit and a Josephson reference amplifier reading unit, wherein the double conversion control unitcomprises an IQ pulse signal source, a first local oscillation signal source, a second local oscillation signal source, a first mixer and a second mixer, a high frequency pulse signal obtained by virtue of the double conversion control unit enters a chip layer by virtue of a transmission layer to perform quantum state conversion on quantum bits, and the Josephson reference amplifier reading unitcomprises a multi-frequency signal modulation and demodulation unit, a signal transmission unit, a chip connection unit and a Josephson reference amplifier unit. The device provided by the invention adopts a double conversion technology for synthesizing the high frequency pulse signal and controlling multiple quantum bits in parallel, so that quantum bit control accuracy and stability are improvedand cost is reduced; and by adding the Josephson reference amplifier, a signal to noise ratio during state measurement is improved, and single shot non-destructive reading on the quantum bits in short time is realized.

A method for monitoring and measuring an insulation resistance in ungrounded and grounded power supply systems includes the method steps of generating a periodic measuring signal, coupling in the measuring signal between active conductors of the power supply system to be monitored and ground, and detecting and evaluating measured values of the measuring signal. In one embodiment of the invention, the generated measuring signal is formed as a multi-frequency signal by the superposition of a finite number of harmonic oscillations with at least three harmonics. Alternatively, the multi-frequency signal can also be realized by means of a targeted, portioned construction of the signal shape in the time domain on the basis of a binary sequence optimization or by generating the measuring signal by means of the time-division multiplexing method.

The invention discloses a method for nondestructive examination of oxide thickness distribution in stainless steel tubes, vortex flow transducer is sticked on external wall of bend section in stainless steel tubes, motivated by a multi-frequency signal, vortex flow sensing signal is obtained by the vortex flow transducer, the signal is processed by a computer processing system into data in correspondence position corresponding to oxide thickness of bend section in stainless steel tubes after signal amplification, phase sensitive detection and frequency mixing of interference signals, whole perisporium of the stainless tube is detected by surrounding, a plurality of data in a plurality of positions correspondinig to oxide thickness of bend section in stainless steel tube to be tested is obtained, the computer processing system proceeds imaging treatment according to data of oxide thickness corresponding to stainless steel tubes, images corresponding to stainless steel tubes for mapping oxide vortex flow sensing signals are obtained; and then a pseudo-three-dimensional image corresponding to shape of stainless steel tube is obtained, and oxide distribution conditioin inside the stainless steel is displayed.

A method and system for magnetically tracking a device of interest generating a plurality of pre-determined multi-frequency signals. The method and system transmits a plurality of magnetic fields from a transmitter circuit based on the corresponding pre-determined multi-frequency signals. The magnetic fields propagating through an area of examination encompassing the device of interest and a magnetic sensor coupled to the device of interest. The method and system generate a sensor signal at the magnetic sensor indicative of field strength of the magnetic fields transmitted by the transmitter circuit. Further, the method and system determine a position of the magnetic sensor relative to the transmitter circuit based on the multi-frequency signals and the sensor signal.

An audio test apparatus, and an exemplary audio test method that includes: processing an audio file through two independent channels; outputting no signals from a left channel and from a right channel in a first time period; receiving noise signals from the left and right channels; outputting single-frequency signals from the left channel only in a second time period; receiving the single-frequency signals from the left channel and crosstalk signals from the right channel; outputting multi-frequency signals from the left and right channels in a third time period; receiving the multi-frequency signals from the left and right channels; outputting single-frequency signals from the right channel only in a fourth time period; receiving the crosstalk signals from the left channel and the single-frequency signals from the right channel; and testing parameters according to the signals received during the four time periods.

The present invention provides a method and system for transmitting a multi-frequency signal composed of discrete tones of constant envelope parts that are amplified by a bank of fully saturated transmitters operating in their most power efficient mode. After amplification and transmission, the signals are multiplexed in the air as opposed to multiplexing before amplification that allows for more efficient amplification as well. In a preferred embodiment, the system has two or more transmitting antennas, and the method comprises: (a) generating a first signal of a first carrier frequency and a second signal of a second carrier frequency; (b) transmitting the first signal of a first carrier frequency on a first antenna and the first signal of a second carrier signal on a second antenna for a predetermined time period; and (c) transmitting a second signal of the second carrier frequency on said first antenna and a second signal of the first carrier frequency on the second antenna for the predetermined time period. Preferably, the signals are transmitted using an amplifier that is essentially fully saturated.

The invention provides a photoelectric oscillator on the basis of stimulated Brillouin scattering amplification effects and a method for regulating the photoelectric oscillator, and relates to the field of photoelectric technologies. The photoelectric oscillator comprises a first laser device, a circulator, an optical fiber unit, a second laser device, a phase modulator, a tunable attenuator, a photoelectric detector unit, a tunable filter, a coupler and a power amplifier. Multi-frequency signals can be generated by laser light outputted by the second laser device via the phase modulator, back Brillouin scattering signals are generated by laser signals outputted by the first laser device in the optical fiber unit, the multi-frequency signals and the back Brillouin scattering signals are subjected to stimulated Brillouin scattering amplification, amplified multi-frequency signals are subjected to attenuation, photoelectric conversion and filtering and then are divided into two channels of signals by the coupler, one channel of signals is used as feedback signals to be inputted into the phase modulator, and the other channel of signals is used as microwave signals to be outputted. The photoelectric oscillator and the method have the advantages that output wavelengths of the first laser device can be changed, accordingly, frequencies of the feedback signals can be changed, the required multi-frequency signals can be obtained, and the tunable microwave signals can be ultimately outputted.