1523 results about "Signal wave" patented technology

An apparatus generates femtosecond pulses from laser amplifiers by nonlinear frequency conversion. The implementation of nonlinear frequency-conversion allows the design of highly nonlinear amplifiers at a signal wavelength (SW), while still preserving a high-quality pulse at an approximately frequency-doubled wavelength (FDW). Nonlinear frequency-conversion also allows for limited wavelength tuning of the FDW. As an example, the output from a nonlinear fiber amplifier is frequency-converted. By controlling the polarization state in the nonlinear fiber amplifier and by operating in the soliton-supporting dispersion regime of the host glass, an efficient nonlinear pulse compression for the SW is obtained. The generated pulse width is optimized by utilizing soliton compression in the presence of the Raman-self-frequency shift in the nonlinear fiber amplifier at the SW. High-power pulses are obtained by employing fiber amplifiers with large core-diameters. The efficiency of the nonlinear fiber amplifier is optimized by using a double clad fiber (i.e., a fiber with a double-step refractive index profile) and by pumping light directly into the inner core of this fiber. Periodically poled LiNbO3 (PPLN) is used for efficient conversion of the SW to a FDW. The quality of the pulses at the FDW can further be improved by nonlinear frequency conversion of the compressed and Raman-shifted signal pulses at the SW. The use of Raman-shifting further increases the tuning range at the FDW. For applications in confocal microscopy, a special linear fiber amplifier is used.

A rectenna includes an antenna configured to receive a radio wave, a rectifier circuit configured to rectify the radio wave received by the antenna, a transmission line connected to the antenna and the rectifier circuit, and a modulation input circuit including a variable capacitance element. The variable capacitance element is connected at one end to a portion of the transmission line between an antenna connecting portion at which the antenna is connected to the transmission line and a rectifier circuit connecting portion at which the rectifier circuit is connected to the transmission line, and is configured such that the capacitance thereof varies in accordance with the voltage of a modulated signal wave input to the other end of the variable capacitance element.

The present invention provides a radio communication device, a transmitter and a receiver capable of handling a plurality of signal waves. A radio communication device has a millimeter-wave transmitter (15) and a millimeter-wave receiver (29). Millimeter-wave transmitter (15) includes a multiplexing circuit (1), a millimeter-wave up-converter (4) and an antenna (3), and the millimeter-receiver includes an antenna (31), a millimeter-wave down-converter (32) and an output processing circuit (45). The signal waves dedicated to the user are modulated by a modulation circuit (121 to 124) so as to be allocated between the ground broadcast waves and satellite broadcast waves. The frequencies are multiplexed in an intermediate frequency band, after that, the multiplexed frequencies are converted into a millimeter-wave band and the resultant is transmitted. On the reception side, the multiplexed waves are down-converted, separated to signal waves and demodulated.

An antenna assembly for wireless communications has various components to minimize signal influence when transmitting signals to minimize undesirable loop formation phenomena caused by (positive) feedback of signals. Signal wave scattering and diffraction causing back lobe radio frequency (RF) patterns are minimized by a particular antenna assembly structure having a reflector and at least one attenuating structural member, a metallic mesh wrapping the power cable of a feeder, a non-conductive antenna support structure, or any combination thereof. The dimensions of the various components, in particular the reflector and attenuators, can be varied according to desired wireless communications environment.

A chest diagnostic support information generation system includes: a radiography section which radiographs a chest portion of a subject; an image analysis section which generates a diagnostic support information based on an image data generated by the radiography section; and a display which displays the diagnostic support information, wherein the radiography section obtains a plurality of frame images which show a motion state of the chest of the subject, and the image analysis section includes: a breathing information generation section which generates the diagnostic support information relating to breathing of the subject based on a difference value of the pixel or the block corresponded with each other between image frames temporally adjacent among the plurality of frame images; and a blood flow information generation section which generates the diagnostic support information relating to blood flow of the subject based on a generated output signal wave form.

The polarization direction of a signal is rotated by a polarization controller so as to be orthogonal to the main axis of a polarizer. A control pulse generator generates control pulses from control source with a wavelength which is different from the wavelength of the signal. The signal and the control pulse are input to a nonlinear optical fiber. In the nonlinear optical fiber, the signal, during the time period in which the signal and the control pulse coincide, has its polarization direction rotated by cross phase modulation, and is amplified by optical parametric amplification. The signal, during the time period in which the signal and the control pulse coincide, passes through the polarizer.

A high-frequency multilayer circuit substrate having a plurality of circuit layers includes a via hole for connection between the circuit layers, a metal pad, an impedance matching transmission line, rectangular stubs and a signal transmission line. A via hole connecting portion is constructed of the via hole, the rectangular stubs and the impedance matching transmission line. A characteristic impedance of the via hole connecting portion is matched to a characteristic impedance of the signal transmission line by adjusting widths and lengths of the impedance matching transmission line and the rectangular stubs. Thereby, the reflection of the signal wave in the via hole connecting portion is reduced to decrease a transmission loss.

The invention relates to a method for detecting and processing the amplitude and phase of signal waves. A Modulated signal source generates the signal waves which are modified by transmission medium or by reflection and scattering by at least one object. The modified signal waves are received and demodulated using a modulation signal. The amplitude of the modulated signal waves and their phase relationship to the modulation signal are measured and evaluated. The demodulated signal wave is converted into an electrical charge or charge displacement in the receiving medium and is distributed in accordance with a modulation signal to at least two readout outputs and fed to an evaluation unit. The evaluation unit produces the sum and difference of the output signals thus applying the value of the intensity and the phase position of the signal wave that has been scattered, reflected or delayed by the object.

A millimeter wave band communication apparatus includes a millimeter wave band transmitter receiving a plurality of input modulation signal waves to transmit a millimeter wave band multiplex signal wave, and a millimeter wave band receiver receiving the transmitted millimeter wave band multiplex signal wave to restore the plurality of input modulation signal waves. The millimeter wave band transmitter includes a frequency arranging circuit generating a multiplex signal wave having respective frequency bands of the plurality of input modulation signal waves arranged on the frequency axis independent of each other, a frequency up-converter up-converting the generated multiplex signal wave to the millimeter wave band, and a transmission circuit transmitting the millimeter wave band multiplex signal wave. The millimeter wave band receiver includes a reception circuit receiving the millimeter wave band multiplex signal wave, a frequency down-converter down-converting the millimeter wave band multiplex signal wave from the millimeter wave band, and a frequency rearranging circuit restoring the down-converted multiplex signal wave into the plurality of input modulation signal waves respectively having the former frequency bands.

The present invention provides an antenna array for ascertaining the distance between vehicles and their speed, which includes devices for receiving or transmitting signal waves, a multi-layer carrier situated underneath the devices, a first potential surface, which is at ground and which is situated on the surface of the carrier facing the devices, coupling devices located in the first potential surface, electrical connecting sections disposed as closely as possible underneath the first potential surface, and a second potential surface which is located underneath the connecting sections and is at mass.

A millimeter band transmitter transmits one or more indirect path signal waves from the main lobe of a transmit antenna, and a direct path signal wave is transmitted in a side lobe of the transmit antenna. A receiver simultaneously receives each of the indirect and direct path signal waves if the receive antenna is unobstructed. If the direct line of sight path between the transmitter and receiver is blocked, the receiver only receives one or more of the indirect path signal waves.

The invention discloses a wavelength-division time-division mixed multiplexing passive optical network system, which at least comprises an optical line terminal, an optical distribution network and a plurality of optical network units. The optical line terminal is used to send downlink optical signal wave bands of a plurality of services, make multiplexing wave coupling to the optical signal wave bands of the plurality of services, then allow the optical signal wave bands to enter the same single fiber and transmit the optical signal wave bands to the optical distribution network; the optical distribution network is used to demultiplex an optical signal which is received from the optical line terminal and wave-coupled, then makes multi-level selective download and transparent transmission to one or a plurality of optical signals after the demultiplexing, and makes power division of one or the plurality of demultiplexed optical signals to the optical network units; the optical network units are used to receive light signals of the plurality of services downloaded by the optical distribution network through a coupling fiber, and logically processes the optical signals. The wavelength-division time-division mixed multiplexing passive optical network system has the advantages of large single-fiber access capacity, low cost of network construction, easy operation maintenance and upgrade and so on.

A compact, tunable, high-efficiency entangled photon source system that utilizes first and second periodically poled waveguides rather than bulk media in order to decrease the required pump power by up to several orders of magnitude. The first and second waveguides are arranged in respective arms of an interferometer. Each waveguide has partially reflecting ends, and are each placed on the Z-face of respective periodically poled KTP or LiNBO3 crystals to form respective first and second Fabry-Perot cavities. All waves (pump, idler, and signal) are co-polarized along the z-axis of the crystals. One of the waveguides is followed by a polarization rotator (shown as a half-wave-plate in the Figures) rotating the idler and signal wave polarization by 90 degrees. The outputs from two interferometer arms are combined by a polarization beam combiner and then split by a wavelength multiplexer into two spatially separated time-bin and polarization entangled beams. Another light source, a single frequency stabilized C-band laser (stabilization laser) is used to synchronize cavities spectral modes and phase-lock their outputs.

The invention discloses a centralized MIMO radar wave shape online designing method mainly aiming to solve the problems that a transmitting direction diagram can not be designed on line and the wave shape of a transmitted signal can not be synthesized on line by utilizing the traditional methods. The method comprises the following steps of: (1) carrying out amplitude weighting on an MIMO radar array, and constructing a fundamental wave beam bank with lower airspace sidelobe off line; (2) based on sequence quadratic programming, constructing various proportions of orthotropic fundamental wave shape banks which have low autocorrelation peak sidelobe level and low peak cross-correlation level off line; (3) solving the transmitting proportion of fundamental wave beams synthetizing the given transmitting direction diagram on line by utilizing linear programming; (4) selecting the fundamental wave shapes meeting the demand from the orthotropic fundamental wave shape banks according to the transmitting proportion of the fundamental wave beams; and (5) respectively synthetizing the transmitting direction diagram and a transmitting signal wave shape by the selected fundamental wave beams and the fundamental wave shapes. Compared with the traditional wave shape designing method, the invention can realize the online wave shape design and can be used for the self-adaption tracking of an MIMO radar on a moving target.

There is provided a dual-band antenna having small size and low height which has a characteristic of not affecting a bandwidth of signal waves of a low band in its miniaturized state. In a dual-band antenna 11, a first radiating conductive plate 13 is arranged to oppose a surface of a grounding conductor 12 in an approximately parallel manner, being excited at a first frequency. A feeding conductive plate 14 extends approximately orthogonally from an outer edge of the first radiating conductive plate 13 and is connected to a feeding circuit A second radiating conductive plate 15 is stood downward the first radiating conductive plate 13, whose lower end is connected to the feeding conductive plate 14. The second radiating conductive plate 15 is excited at a second frequency. A third radiating conductive plate 17 is arranged to oppose the surface of the grounding conductor 12 in an approximately parallel manner on a surface of the grounding conductor and to be adjacent to the first radiating conductive plate 13. A slit 18 is interposed between both radiating conductive plates 13 and 17. A shorting conductive plate 19 extends approximately orthogonally from an outer edge of the third radiating conductive plate 17 and is connected to the surface of the grounding conductor 12. The feeding conductive plate 14 and the shorting conductive plate 19 is arranged close to each other, such that, when a power is supplied, the feeding conductive plate 14 and the shorting conductive plate 19 is electromagnetically coupled.

The invention discloses a transformer substation local discharge positioning method based on electromagnetic antenna array signal processing. The transformer substation local discharge positioning method is finished by a local discharge detection device, and the local discharge detection device comprises an omnidirectional antenna array, a built-in amplifier, a super-high-speed data sampling unit and a data processing unit which are mounted in a transformer substation. The positioning method comprises the steps as follows: constructing a matrix according to a concept of working out a signal wave arrival direction by a rotation invariant technology based on L-shaped antenna array signal processing; obtaining an azimuth angle of a local discharge source arriving at an antenna; and finishing planar location of the local discharge source of the transformer substation. A time delay sequence of a signal does not need to be calculated, so that the requirement on a sampling rate of an acquisition system can be lowered; and a plane coordinate of the local discharge source is obtained by working out a linear cross point in two wave arrival directions, namely working out a linear equation set in two unknowns, so that calculation of a nonlinear equation set is avoided.

The invention relates to an interference noise matrix reconstitution-based self-adaptive wave beam forming method and belongs to the field of array signal processing. The method comprises the steps of firstly establishing the signal model of a minimum variance distortionless response wave beam forming problem, then under the condition that the angle range of an expected signal wave arrival direction is known, utilizing a multiple signal sorting spatial spectrum to reconstitute an interference noise covariance matrix in a region without containing expected signals, based on the matrix, solving the estimation value of a guide vector of the real expected signal by using the maximizing of an array output power and the constrain condition that the estimation value of the guide vector of the expected signal is prevented from being converged to the guide vector of any interference or the linear combination of the interference. According to the method, a simulation result shows that when random pointing errors and local scattering of the expected signal and a interference source exist, the output signal to interference plus noise power ratio in a very large input signal-to-noise ratio range is still close to a theoretical value and is superior to that of other self-adaptive wave bean forming methods.