A novel approach to estimating the Doppler shift frequency from quadrature mixer output

2017 ◽  
Vol 88 (7) ◽  
pp. 073503 ◽  
Author(s):  
M. Y. Wang ◽  
A. D. Liu ◽  
C. Zhou ◽  
J. Q. Hu ◽  
H. Li ◽  
...  
Keyword(s):  
Doppler Shift ◽  
Novel Approach ◽  
Shift Frequency

Shear-Layer Detection in Poststenotic Flow by Spectrum Analysis of Doppler Signals

1988 ◽  
Vol 110 (4) ◽  
pp. 320-325 ◽  
Author(s):  
T. Tamura ◽  
A. Fronek
Keyword(s):  
Shear Layer ◽  
Spectrum Analysis ◽  
Doppler Shift ◽  
Continuous Wave ◽  
Reverse Flow ◽  
Separated Flow ◽  
Sample Volume ◽  
Doppler Spectrum ◽  
Doppler Signals ◽  
Shift Frequency

Spectrum analysis of the Doppler signals was performed 0.5 tube diameters downstream from an axisymmetric constriction with an area reduction of 80 percent in steady flow at a jet Reynolds number of 2840. Both pulsed and continuous wave (CW) Doppler spectra showed significant reverse flow components in the separated flow. The pulsed Doppler spectra exhibited sudden changes when the sample volume crossed the shear layer between the center jet and the separated flow. A power spectrum equation was theoretically derived from continuity of flow to define the Doppler shift frequency for the shear layer velocity. The CW Doppler spectrum showed a minimum spectrum density at a frequency which equalled the shear layer Doppler shift frequency derived from the equation. The pulsed spectra exhibited the sudden changes at the same frequency as well.

Effect of Doppler Shift frequency on the performance of 2x2 OSTBC-OFDM System

2017 ◽  
Vol 2 (2) ◽  
Author(s):  
Diana Hayder Hussein ◽  
Thuraya Mahmood Qaradaghi
Keyword(s):  
Doppler Shift ◽  
Ofdm System ◽  
Shift Frequency

Precision Force Measurement Using the Levitation Mass Method (LMM)

2011 ◽  
Vol 103 ◽  
pp. 1-8
Author(s):  
Yusaku Fujii ◽  
Akihiro Takita ◽  
Jakrapong Kaewkhao ◽  
Mitra Djamal ◽  
Takao Yamaguchi
Keyword(s):  
Laser Beam ◽  
Doppler Shift ◽  
Measurement Method ◽  
Force Measurement ◽  
Inertial Force ◽  
High Accuracy ◽  
Optical Interferometer ◽  
Future Prospects ◽  
Mechanical Measurement ◽  
Shift Frequency

This paper reviews the present status and future prospects of the levitation mass method (LMM), which is a precision mechanical measurement method. The LMM has been proposed and improved by the author for 10 years. The force generated by the actuator is measured as the inertial force of the mass levitated with sufficiently small friction using an aerostatic linear bearing and connected to the moving part of the actuator. During the measurement, the Doppler shift frequency of the laser beam reflected by the mass is measured with a high accuracy with the help of an optical interferometer. Subsequently, the velocity, position, acceleration, and inertial force of the mass are calculated using based on this frequency. Simultaneously, the current and voltage supplied to the actuator are measured.

Development of Material Tester Using Pendulum

2011 ◽  
Vol 497 ◽  
pp. 176-181
Author(s):  
Hironori Ebara ◽  
Akihiro Takita ◽  
Tomohiko Azami ◽  
Yusaku Fujii
Keyword(s):  
Doppler Shift ◽  
Mechanical Characteristics ◽  
Inertial Force ◽  
Inertia Force ◽  
Materials Testing ◽  
Optical Interferometer ◽  
Measured Time ◽  
Small Force ◽  
Shift Frequency ◽  
Measuring Force

The requirements for evaluating the mechanical characteristics of materials have increased in the various industrial, research and the applications such as materials testing. Therefore, the authors have proposed a method for measuring force acting a material using pendulum [1]. In the Material tester, the mechanical characteristics of material against small force are measured by means of the pendulum mechanism based on the levitation mass method (LMM) [2,3,4].In the LMM, the Doppler shift frequency is measured for measuring the inertial force. The Doppler shift frequency of a laser beam reflected from the mass is accurately measured by using optical interferometer. The velocity, position, acceleration and inertia force of the mass are calculated from the measured time-varying Doppler shift frequency. Thus, the accurate measure of frequency makes that of force.

Doppler Shift Frequency to Voltage Conversion Techniques

1975 ◽  
pp. 592-592
Author(s):  
F. D. McLeod ◽  
R. Daigle ◽  
C. W. Miller
Keyword(s):  
Doppler Shift ◽  
Shift Frequency ◽  
Voltage Conversion
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