公开(公告)号：US20190066626A1

公开(公告)日：2019-02-28

申请号：US15688196

申请日：2017-08-28

Applicant: NATIONAL INSTRUMENTS CORPORATION

Inventor： Hojin Kee ,  Tai A. Ly ,  Adrian P. Deac ,  Adam T. Arnesen

IPC: G09G5/00 ,  G06F1/08 ,  G11C7/10 ,  G06F17/30 ,  G06F17/18 ,  G06F17/50 ,  G01R31/3185

Abstract: Hardware may be created with different clock speeds used for different components of the system. Clock and throughput requirements on the interface circuitry of hardware components may set limits which are lower requirements for functional components. It may be advantageous to use more or fewer of some functional blocks or interface circuits in order to reduce cost, increase performance or reliability, reduce the requirements for additional parts, or other beneficial factors. Accordingly, it may be advantageous to generate hardware utilizing more than a single clock frequency. Generating instructions which indicate different clock frequencies for separate components may be difficult or time consuming; generating these instructions automatically may provide significant benefits in time savings, increased productivity, increased performance of hardware, or other benefits.

公开(公告)号：US10175334B2

公开(公告)日：2019-01-08

申请号：US14105999

申请日：2013-12-13

Applicant: NATIONAL INSTRUMENTS CORPORATION

Inventor： Christopher G. Regier ,  Pablo Limon

IPC: G01R35/00

Abstract: Systems and methods for calibration and operation of a source-measure unit (SMU). The system may include a functional unit and output terminals coupled to the functional unit. An excitation signal may be applied to a capacitor by the SMU. The capacitor may be included in a calibration circuit. The method may include obtaining one or more of a current calibration coefficient (CCC) or a voltage calibration coefficient (VCC). The CCC may correspond to a current-range setting and the VCC may correspond to a voltage-range setting. The CCC may be obtained from a value of a first current and a value of a second current developed in the capacitor responsive to the excitation signal. The VCC may be obtained from a value of a first voltage and a value of a second voltage developed across the capacitor responsive to the excitation signal.

公开(公告)号：US20180314553A1

公开(公告)日：2018-11-01

申请号：US16027773

申请日：2018-07-05

Applicant: NATIONAL INSTRUMENTS CORPORATION

Inventor： Sundeep Chandhoke ,  Herbert K. Salmon, IV

IPC: G06F9/48

CPC classification number: G06F9/4887 ,  G06F9/4825 ,  G06F2209/486

Abstract: A method and system for scheduling a time critical task. The system may include a processing unit, a hardware assist scheduler, and a memory coupled to both the processing unit and the hardware assist scheduler. The method may include receiving timing information for executing the time critical task, the time critical task executing program instructions via a thread on a core of a processing unit and scheduling the time critical task based on the received timing information. The method may further include programming a lateness timer, waiting for a wakeup time to obtain and notifying the processing unit of the scheduling. Additionally, the method may include executing, on the core of the processing unit, the time critical task in accordance with the scheduling, monitoring the lateness timer, and asserting a thread execution interrupt in response to the lateness timer expiring, thereby suspending execution of the time critical task.

公开(公告)号：US10103928B2

公开(公告)日：2018-10-16

申请号：US15486537

申请日：2017-04-13

Applicant: National Instruments Corporation

Inventor： James Wesley McCoy ,  Lothar Wenzel

IPC: H04K1/02 ,  H04L25/03 ,  H04L25/49 ,  H04L27/36 ,  H04B1/10 ,  H04B1/04 ,  H04L27/38

Abstract: Nyquist filters for pulse shaping and related matched filters in wireless communications are disclosed that provide improved performance. The disclosed embodiments recognize that the second derivative of the raised cosine function is discontinuous in the frequency domain and that the first derivative of the square root raised cosine is discontinuous in the frequency domain. As such, a generalization for the raised cosine filter is applied, and improvements can be made to the raised cosine function time-frequency localization and ultimately to tradeoffs between inter-symbol interference and adjacent channel interference by introducing smoothness to the higher order derivatives of the frequency response.

公开(公告)号：US10069400B1

公开(公告)日：2018-09-04

申请号：US15827588

申请日：2017-11-30

Applicant: NATIONAL INSTRUMENTS CORPORATION

Inventor： Larry D. Morgan, Jr. ,  Raymundo J. Medina

IPC: H02J1/02 ,  H02M1/12 ,  H02M1/14 ,  H02M1/00 ,  H02M7/538 ,  H02M1/44 ,  H02M3/337 ,  H02M3/07

Abstract: A residual current (e.g. common-mode current) may be present in an isolated subsystem. The isolated subsystem may include the secondary winding of a transformer while a first subsystem may include the primary winding of the transformer. The first subsystem may also include a compensation circuit. A driver circuit may generate drive signals provided to the primary winding of the transformer and also to the compensation circuit. The compensation circuit may include a variable capacitor network (e.g. a variable capacitor diode network) that receives the drive signals and also receives a bias voltage, and generates a cancellation signal according to the drive signals and the bias voltage. The compensation circuit may provide the cancellation signal to the ground plane of the isolated subsystem through a capacitor that couples the variable capacitor diode network to the ground plane, in order to reduce or cancel the residual current present in the isolation subsystem.

公开(公告)号：US20180206236A1

公开(公告)日：2018-07-19

申请号：US15918905

申请日：2018-03-12

Applicant: NATIONAL INSTRUMENTS CORPORATION

Inventor： Stephen L. Dark ,  Daniel J. Baker ,  Johnathan R. W. Ammerman

IPC: H04W72/04 ,  H04B1/00 ,  H03M1/12 ,  G01R23/165 ,  G01R13/02

CPC classification number: H04W72/0453 ,  G01R13/0272 ,  G01R23/165 ,  H03M1/121 ,  H04B1/0003 ,  H04B1/0025

Abstract: Embodiments are described of devices and methods for processing a signal using a plurality of vector signal generators (VSGs). A digital signal may be provided to a plurality of signal paths, each of which may process a respective frequency band of the signal, the respective frequency bands having regions of overlap. The gain and phase of each signal path may be adjusted such that continuity of phase and magnitude are preserved through the regions of overlap. The adjustment of gain and phase may be accomplished by a complex multiply with a complex calibration constant. The calibration constant may be determined for each signal path by comparing the gain and phase of one or more calibration tones generated within each region of overlap. Each signal path may comprise a VSG to convert the respective signal to an analog signal, which may be combined to obtain a composite signal.

公开(公告)号：US10019286B2

公开(公告)日：2018-07-10

申请号：US15167638

申请日：2016-05-27

Applicant: NATIONAL INSTRUMENTS CORPORATION

Inventor： Sundeep Chandhoke ,  Herbert K. Salmon, IV

IPC: G06F9/46 ,  G06F9/48

CPC classification number: G06F9/4887 ,  G06F9/4825 ,  G06F2209/486

Abstract: A method and system for scheduling a time critical task. The system may include a processing unit, a hardware assist scheduler, and a memory coupled to both the processing unit and the hardware assist scheduler. The method may include receiving timing information for executing the time critical task, the time critical task executing program instructions via a thread on a core of a processing unit and scheduling the time critical task based on the received timing information. The method may further include programming a lateness timer, waiting for a wakeup time to obtain and notifying the processing unit of the scheduling. Additionally, the method may include executing, on the core of the processing unit, the time critical task in accordance with the scheduling, monitoring the lateness timer, and asserting a thread execution interrupt in response to the lateness timer expiring, thereby suspending execution of the time critical task.

公开(公告)号：US20180188306A1

公开(公告)日：2018-07-05

申请号：US15398074

申请日：2017-01-04

Applicant: NATIONAL INSTRUMENTS CORPORATION

Inventor： Prabhat Pal ,  Vinay Kumar Velkuru ,  Brian J. Avenell

IPC: G01R29/26 ,  G01R27/28

CPC classification number: G01R29/26 ,  G01R27/28

Abstract: The noise figure for a radio frequency device may be obtained through power measurements. A signal flow graph based upon the S-parameter information of the entire RF system may be constructed. The S-parameter information may be representative of the microwave termination, the device, the measurement instrument and any losses due to additional components such as connecting cables/attenuators/switches, etc. The signal flow graph includes proper placement and values of the source nodes corresponding to each RF sub-system enumerated above. Noise figure measurements may include a calibration step and a measurement step. During the calibration step the noise figure and the noise temperature of the measurement instrument used for the measurement may be obtained. During the measurement step, the noise figure and the noise temperature of the device may be obtained based at least on the noise figure and noise temperature of the measurement instrument obtained during the calibration step.

公开(公告)号：US09995638B2

公开(公告)日：2018-06-12

申请号：US14871041

申请日：2015-09-30

Applicant: NATIONAL INSTRUMENTS CORPORATION

Inventor： Daniel H. Ousley ,  Shaun M. Stelley ,  David R. Pasternak

IPC: G01K13/00 ,  G01K7/02 ,  G01K7/13

CPC classification number: G01K7/13

Abstract: Input terminal of a thermocouple (TC) instrument. The input terminal may include a printed circuit board (PCB), including an input portion configured to receive signals from a thermocouple, and an output portion configured to communicatively connect to the instrument. The input terminal may further include a sensor mounted on the PCB, configured to measure temperature at or near a cold junction of the input terminal. The PCB may include first traces connecting the input portion of the PCB to the output portion of the PCB, and configured to send TC signals to the TC instrument and second traces connecting the sensor to the output portion of the PCB, and configured to send temperature signals to the instrument. The traces may be configured to provide the TC signals and the temperature signals to the TC instrument without using metal pins.

公开(公告)号：US20180159637A1

公开(公告)日：2018-06-07

申请号：US15821473

申请日：2017-11-22

Applicant: NATIONAL INSTRUMENTS CORPORATION

Inventor： Tanim Mohammed Abu Taher ,  Ahsan Aziz ,  James W. McCoy

IPC: H04B17/12 ,  H04L25/03 ,  H04B7/0413

CPC classification number: H04B17/12 ,  H04B7/0413 ,  H04B17/14 ,  H04B17/21 ,  H04L25/0202 ,  H04L25/03012 ,  H04L25/03159 ,  H04L25/03891

Abstract: Techniques are disclosed related to calibrating and operating a multiple input multiple output (MIMO) radio system. In some embodiments, a dual mode calibration may be employed to calibrate a remote transmitter (RT). During a first, Sparse Full System Calibration (SFSC) mode, the RT may be physically connected to the MIMO radio system. In some embodiments, first and second equalizers may be derived for each of the RT and a local transmitter (LT), respectively. During a subsequent, Real-time Calibration (RTC) mode, the RT may be located remotely from the MIMO radio system, and the RT may be configured to communicate with the MIMO radio system over the air via an antenna. In the RTC mode, third equalizers may be derived for the LT. The RT may then be calibrated based on an equalizer that is derived from each of the first, second, and third equalizers. As one non-limiting example, the techniques described herein may enable real-time calibration for the RT even while the RT is located remotely from the MIMO radio system. In different embodiments, the calibration may be achieved by deriving either fractionally spaced frequency domain equalizers, or time domain equalizers.