Patents
Literature
Patsnap Copilot is an intelligent assistant for R&D personnel, combined with Patent DNA, to facilitate innovative research.
Patsnap Copilot

7355results about How to "Improve linearity" patented technology

High efficiency linearization power amplifier for wireless communication

An embodiment of the invention uses a predistortion correction signal to combination the modulated RF signal by an analog multiplier for linearization of power amplifiers having nonlinear characteristics such as those used in wireless RF transmitters. A predistortion controller comprises a plurality of down converters for retrieving both the ideal non-distorted information and the feedback distorted information, together with pre-stored digitally-indexed predistortion information stored, for example, in a look-up table. The digitally-indexed information models nonlinear characteristics of the high power amplifier, and is stored prior to processing of pre-compensation in the power amplifier. When the predistortion information is combined with the modulated RF signal in the analog multiplier, the result is a substantially linear information transmission from the power amplifier. In an embodiment of the system, the modulated RF input signal and the feedback signal from PA output are down-converted, respectively, by analog devices, such as mixers, after which the analog intermediate frequency (IF) signals are digitized by analog-to-digital converters for digital predistortion correction processing, followed by predistortion processing performed by, for example, a DSP or FPGA chip to generate a digital correction control signal, which is then converted to an analog signal by a digital-to-analog converter, followed by combining the analog correction signal with the RF modulated input signal to yield the input to the power amplifier.
Owner:DALI WIRELESS

Fluid damper having continuously variable damping response

An improved damping apparatus that utilizes a fluid having a viscosity that may be varied by the application of an electromagnetic field, such as a magnetorheological fluid or an electrorheological fluid, to provide the damping response. The damping apparatus includes a linear to rotary conversion mechanism which comprises a translatable member that is adapted for linear translation in a forward and a reverse direction and a rotatable member comprising a rotatable shaft that is rotatably coupled to the translatable member; wherein translation of the translatable member in one of the forward or the reverse directions produces a forward or a reverse rotation of the rotatable member and shaft, respectively. The damping apparatus also includes a damping mechanism which comprises a hub that is fixed to the shaft, a means for generating a variable electromagnetic field in response to an applied electrical signal that may be continuously varied in response to an input signal that is representative of a desired damping force and a fluid having a viscosity that may be continuously varied by application of the electromagnetic field that is in touching contact with the hub. Application of the variable electromagnetic field to the fluid produces changes in the viscosity of the fluid that in turn provides variable resistance to rotation of the hub and resistance to translation of the translatable member, thereby providing a damping apparatus with a continuously variable damping response.
Owner:GM GLOBAL TECH OPERATIONS LLC

Method for constructing radio frequency front end of multi-mode multi-band satellite navigation receiver and module thereof

The invention discloses a configurable multi-mode multi-band satellite navigation receiving method and a radio frequency front end module constructed by the method. The front end module can receive signals of satellite navigation and positioning systems such as a global positioning system (GPS), the Big Dipper, a Galileo positioning system and a global navigation satellite system (Glonass), and comprises a configurable low-noise amplifier (LNA) with a buffer and an active balun, a folding passive mixer with a configurable frequency synthesizer, a configurable multi-mode filter, an automatic gain control (AGC) amplifier, a direct-current bias circuit, and a multi-mode multi-band program controlled and coded on-off control word from a receiving system. The radio frequency front end module can meet the requirement of multi-band multi-mode work through the control word programmed by the receiving system, has a simple and reliable structure, does not need complicated time division multiplexing control system and off-chip module, has low cost and high flexibility, and improves the noise performance of the radio frequency front end of the whole receiver and multi-mode multi-band signal processing capacity; and a one-channel signal is input into the module, and the module outputs a two-channel differential signal. The receiver can be used for receiving and processing multi-mode satellite navigation signals asynchronously, and receiving and processing satellite navigation signals with the required mode in different time intervals according to the requirement.
Owner:杭州中科微电子有限公司

Position sensing with improved linearity

A position-sense interface with improved transfer characteristics. Electrical position detection circuitry, which may be substantially time-multiplexed or frequency-multiplexed, comprises a differential charge integrator with input-sensed output-driven common mode feedback. By placing sense capacitors in the feedback loop of said differential charge integrator with input-sensed output-driven common mode feedback, improved position sensing linearity is attained. In some embodiments of the invention, a compensating charge is applied to the sense capacitors in a fashion that minimizes the output common mode shift of the opamp. The magnitude of the compensating charge may be preset at a substantially constant level, or derived by a feedback loop that measures the shift in output common mode voltage in response to an excitation signal and adjusts the magnitude of the compensating charge to drive said shift towards zero.
The invention has numerous advantages for acceleration measurement in both open-loop and force-balanced accelerometers, as well as rotation rate measurement in a vibratory rate gyroscope. Other applications in which the invention may prove advantageous include: motion detection for an oscillation-sustaining feedback loop; position detection of actuators, including micro-actuators used for effecting controlled motion of a disk-drive read/write head, or effecting controlled motion of an optically active device, such as a positionable mirror for use in fiber-optic data communications; and application of electrostatic forces for large motions.
Owner:ANALOG DEVICES IMI
Who we serve
  • R&D Engineer
  • R&D Manager
  • IP Professional
Why Eureka
  • Industry Leading Data Capabilities
  • Powerful AI technology
  • Patent DNA Extraction
Social media
Try Eureka
PatSnap group products