207results about How to "Solve narrow bandwidth" patented technology

The invention relates to a method and system for wideband digital pre-distortion linearization, which is used to overcome the influence of memory effect in radio frequency power amplifier, to expand digital pre-distortion linearization bandwidth, and to improve digital pre-distortion linearization performance. The method and system can get an in-band pre-distortion signal and an out-of-band pre-distortion signal according to the characteristic parameter of the amplifier; the in-band pre-distortion signal is up-converted and the up-converted signal is added to the out-of-band pre-distortion signal, which is not up-converted, then the combined signal is inputted to the power amplifier as an input signal; a part of the output signal from the power amplifier, serving as a feedback signal, can be compared with the original input signal, and the characteristic parameter of the amplifier for generating the in-band pre-distortion signal and the out-of-band pre-distortion signal is adaptively regulated according to the comparison result, so that the waveform of time domain or the frequency domain of the feedback signal can be close to that of the original input signal as much as possible.

An efficient, low-loss, low sidelobe, high dynamic range phased-array radar antenna system is disclosed that uses metamaterials, which are manmade composite materials having a negative index of refraction, to create a biconcave lens architecture (instead of the aforementioned biconvex lens) for focusing the microwaves transmitted by the antenna. Accordingly, the sidelobes of the antenna are reduced. Attenuation across microstrip transmission lines may be reduced by using low loss transmission lines that are suspended above a ground plane a predetermined distance in a way such they are not in contact with a solid substrate. By suspending the microstrip transmission lines in this manner, dielectric signal loss is reduced significantly, thus resulting in a less-attenuated signal at its destination.

A circuit for matching the impedance of an output load to an active device includes a transformer including a first winding having a terminal for coupling to the output of the active device and a second winding electromagnetically coupled to the first winding, and a plurality of taps, each of the plurality of taps having a first end coupled to a position on the second winding corresponding to a ratio of the second winding to first winding differing from other ones of the plurality of taps, and a second end. The matching circuit further includes a plurality of MEMS switches each having a control input for receiving a corresponding control signal, a first terminal coupled to the second end of a corresponding one of the plurality of taps, and a switched output selectively coupled to a matching junction in response to the corresponding control signal.

A tunable transmissive grating comprises a transmissive dispersive element, a reflective element, and an angle θ formed between the two elements. A first optical path is formed according to the angle θ, wherein light dispersing from the dispersive element is directed onto the reflective element and reflects therefrom. At least one element is rotatable about a rotational center to cause a second optical path and thereby tune the wavelength of the light reflecting from the reflective element. Both elements can be rotatable together around a common rotational center point according to certain embodiments, and/or each element can be independently rotated around a rotational axis associated only with that element. According to some embodiments, the relative angle θ formed between the elements is held constant; however, in other embodiments θ can vary.

The present disclosure relates to a method and an antenna for transmitting/receiving a RF signal at a plurality of different frequencies. Transmitting/receiving a RF signal at a plurality of different frequencies is achieved by providing a F antenna comprising a plurality of switches which can be used to adjust the resonant frequency of the antenna. By providing a F antenna, the antenna will be much smaller than the wavelength at which the antenna is operating. This allows the antenna to be used in compact devices such as PDA's and cellular phones.

The present invention provides for a one or more layer graphene optical modulator. In a first exemplary embodiment the optical modulator includes an optical waveguide, a nanoscale oxide spacer adjacent to a working region of the waveguide, and a monolayer graphene sheet adjacent to the spacer. In a second exemplary embodiment, the optical modulator includes at least one pair of active media, where the pair includes an oxide spacer, a first monolayer graphene sheet adjacent to a first side of the spacer, and a second monolayer graphene sheet adjacent to a second side of the spacer, and at least one optical waveguide adjacent to the pair.

A microresonator sensor apparatus has a microcavity resonator that defines equatorial whispering gallery modes (EWGMs), whose frequencies are separated by the free spectral range (FSR). The EWGMs lie in a plane perpendicular to a microcavity resonator axis. A light source is optically coupled to inject light into the microcavity resonator. The light source produces output light having an output spectrum whose bandwidth is approximately equal to or broader than the FSR of the EGWMs. One or more fluorescent materials are excited using the excitation light coupled into the microcavity resonator. A fluorescent signal arising from fluorescence of the one or more fluorescent materials is then detected.

A reconfigurable multi-processor computing system including a plurality of configurable processing elements each having a plurality of integrated high-speed serial input/output ports. Interconnects link the plurality of processing elements, wherein at least one of the integrated high-speed serial input/output ports of each processing element is connected by at least one interconnect to at least one of the integrated high-speed serial input/output ports of each other processing element, thereby creating a full mesh network. The full mesh network is located on a processor card, multiples of which may be grouped in a shelf having a backplane card with a shelf controller card for providing cross-connects between processor cards. Multiple shelves may be interconnected to form a large computer system.

A channel sounding method in a wireless local area network (WLAN) system is provided. The method, performed by a transmitter, includes transmitting a null data packet announcement (NDPA) frame to a receiver to initiate a channel sounding procedure; transmitting a null data packet (NDP) to the receiver and receiving a feedback frame. The feedback frame includes a plurality of segment frames and a channel feedback report. The channel feedback report is split into a plurality of feedback segments. Each of the plurality of feedback segments is respectively included in each of the plurality of segment frames. The each of the plurality of segment frames includes a first-segment subfield indicating whether the each of the plurality of feedback segment included is a first segment and a remaining-segment subfield indicating the number of remaining feedback segments.

Interactive multi-view video presents new types of video capture systems, video formats, video compression algorithms, and services. Many video cameras are allocated to capture an event from various related locations and directions. The captured videos are compressed in control PCs and are sent to a server in real-time. Users can subscribe to a new type of service that allows users to connect to the servers and receive multi-view videos interactively. In one embodiment of the invention, an automatic pattern-free calibration tool is employed to calibrate the multiple cameras. In contrast with a pattern-based method which uses the correspondences between image points and pattern points, the pattern-free calibration method is based on the correspondences between image points from different views.

A system comprising a personal computer configured to operate with another computer connected to a network of computers. The personal computer includes a microchip having a microprocessor with a control unit and at least two processing units, the control unit being configured to allow a user of the personal computer to control the two processing units, and the microchip including a power management component. The personal computer includes an internal firewall configured to allow and/or deny access to portions of the microchip both to the user of the personal computer and to a user of the microchip from the network of computers during a shared use of the microchip; and the internal firewall is configured to deny access to portions of the microchip from the network of computers.

A DSP (Digital Signal Processing) architecture with a wide memory bandwidth and a memory mapping method thereof. The DSP architecture includes: a first communication port; first, second, and third memory devices, which are connected with the first communication port and are arranged in a first row direction of the DSP architecture; a fourth memory device, a calculation element, and a fifth memory device, which are arranged in a second row direction below a first row direction of the DSP architecture; and sixth, seventh, and eighth memory devices, which are connected with the first communication port and arranged in a third row direction of the DSP architecture, wherein the calculation element is connected with the first through the eight memory devices. In the DSP architecture, the calculation element and the first through the eighth memory devices form one arrangement unit, wherein the calculation element is disposed in the center of the arrangement unit, the first through the eighth memory devices are connected to the calculation element, and a plurality of arrangement units are arranged in row directions and column directions of the DSP architecture. Therefore, since a wide data bandwidth is provided between the calculation element of the DSP architecture and the memory devices, it is possible to reduce memory access times when data is processed, and accordingly, to process data with a high data rate, such as a moving image with a high resolution.

A thin-film coil assembly includes a flexible substrate, an oscillation starting antenna, a resonant antenna, a first protective layer and a second protective layer. The flexible substrate has a first surface and a second surface opposed to the first surface. The oscillation starting antenna is disposed on the first surface of the flexible substrate. The resonant antenna is disposed on the second surface of the flexible substrate. Moreover, at least one capacitor is connected between a first end and a second end of the resonant antenna. An electromagnetic wave with a specified resonant frequency is emitted or received by the thin-film coil assembly in response to a resonant coupling effect of the resonant antenna and the oscillation starting antenna. The first protective layer covers the oscillation starting antenna. The second protective layer covers the resonant antenna.

A resonator system wherein a plurality of resonators each including piezoelectric material are suspended relative to a substrate. An edge of each resonator is mechanically coupled to an edge of another resonator and the plurality of resonators expand and contract reaching resonance in response to an applied electric field.