Design of wideband complex ratio measuring unit (CRMU) in multilayer microstrip-slot technology for the application of QPSK modulator

2012 ◽  
Author(s):  
S. N. A. Mohamed Ghazali ◽  
Norhudah Seman ◽  
M. K. A. Rahim ◽  
S. K. A. Rahim
Keyword(s):  
Complex Ratio ◽  
Measuring Unit

Design of complex ratio measuring unit (CRMU) for 2 to 6 GHz WiMAX applications

2012 ◽  
Author(s):  
S.N.A.M. Ghazali ◽  
Norhudah Seman ◽  
M. K. A. Rahim ◽  
S. K. A. Rahim ◽  
R.C. Yob
Keyword(s):  
Complex Ratio ◽  
Measuring Unit

DESIGN OF A COMPLEX RATIO MEASURING UNIT USING ENHANCED BRANCH-LINE COUPLER FOR WIRELESS COMMUNICATION APPLICATIONS

2015 ◽  
Vol 77 (10) ◽  
Author(s):  
Nor Azimah Mohd Shukor ◽  
Norhudah Seman
Keyword(s):  
Measurement Unit ◽  
Tight Coupling ◽  
Ground Structure ◽  
Ratio Measurement ◽  
Branch Line ◽  
S Parameter ◽  
Complex Ratio ◽  
5 Ghz ◽  
Advanced System ◽  
Measuring Unit

This article presents the complex ratio measurement unit (CRMU) design formed by enhanced 3-dB branch-line couplers (BLCs), which are placed symmetrically. The first CRMU is formed by four wideband 3-dB BLCs implementing Defect Ground Structure (DGS) and stub impedance techniques that operate over the frequency of 2.5 to 4 GHz. Meanwhile, the other CRMU is formed by four reduced size of enhanced two-section microstrip-slot BLCs with tight coupling of 3-dB over frequency of 2 to 5 GHz. The performances of the CRMU designs are observed and analyzed. The BLCs and CRMUs are designed using CST Microwave Studio. While, the S-parameter performances of the CRMUs are analyzed using Keysight’s Advanced System (ADS) software.

Broadband and compact complex ratio measuring unit

2018 ◽  
Vol 60 (12) ◽  
pp. 3039-3045 ◽  
Author(s):  
Nadera Najib Al-Areqi ◽  
Kok Yeow You
Keyword(s):  
Complex Ratio ◽  
Measuring Unit

scholarly journals A Track Geometry Measuring System Based on Multibody Kinematics, Inertial Sensors and Computer Vision

Sensors ◽  
2021 ◽  
Vol 21 (3) ◽  
pp. 683
Author(s):  
José L. Escalona ◽  
Pedro Urda ◽  
Sergio Muñoz
Keyword(s):  
Computer Vision ◽  
Inertial Sensors ◽  
Vision System ◽  
Accurate Method ◽  
Sensor Data ◽  
Measuring System ◽  
Railway Vehicles ◽  
Track Geometry ◽  
Video Cameras ◽  
Measuring Unit

This paper describes the kinematics used for the calculation of track geometric irregularities of a new Track Geometry Measuring System (TGMS) to be installed in railway vehicles. The TGMS includes a computer for data acquisition and process, a set of sensors including an inertial measuring unit (IMU, 3D gyroscope and 3D accelerometer), two video cameras and an encoder. The kinematic description, that is borrowed from the multibody dynamics analysis of railway vehicles used in computer simulation codes, is used to calculate the relative motion between the vehicle and the track, and also for the computer vision system and its calibration. The multibody framework is thus used to find the formulas that are needed to calculate the track irregularities (gauge, cross-level, alignment and vertical profile) as a function of sensor data. The TGMS has been experimentally tested in a 1:10 scaled vehicle and track specifically designed for this investigation. The geometric irregularities of a 90 m-scale track have been measured with an alternative and accurate method and the results are compared with the results of the TGMS. Results show a good agreement between both methods of calculation of the geometric irregularities.

scholarly journals ANALYTICAL METHODS FOR CALCULATING FAN AERODYNAMICS

2015 ◽  
Vol 55 (6) ◽  
pp. 373
Author(s):  
Jan Dostal ◽  
Jan Kuzel
Keyword(s):  
Mathematical Model ◽  
Analytical Methods ◽  
Preliminary Design ◽  
Computer Programme ◽  
Aerospace Research ◽  
Model Based ◽  
The Creation ◽  
The Mathematical Model ◽  
Measuring Unit

This paper presents results obtained between 2010 and 2014 in the field of fan aerodynamics at the Department of Composite Technology at the VZLÚ aerospace research and experimental institute in Prague – Letnany. The need for rapid and accurate methods for the preliminary design of blade machinery led to the creation of a mathematical model based on the basic laws of turbomachine aerodynamics. The mathematical model, the derivation of which is briefly described below, has been encoded in a computer programme, which enables the theoretical characteristics of a fan of the designed geometry to be determined rapidly. The validity of the mathematical model is assessed continuously by measuring model fans in the measuring unit, which was developed and manufactured specifically for this purpose. The paper also presents a comparison between measured characteristics and characteristics determined by the mathematical model as the basis for a discussion on possible causes of measured deviations and calculation deviations.

scholarly journals Measurements and Accuracy Evaluation of a Strapdown Marine Gravimeter Based on Inertial Navigation

Sensors ◽  
2018 ◽  
Vol 18 (11) ◽  
pp. 3902 ◽  
Author(s):  
Wei Wang ◽  
Jinyao Gao ◽  
Dongming Li ◽  
Tao Zhang ◽  
Xiaowen Luo ◽  
...  
Keyword(s):  
Coupling Effect ◽  
Inertial Navigation ◽  
Satellite System ◽  
Gravity Survey ◽  
Accuracy Evaluation ◽  
Earth’S Gravity Field ◽  
Marine Gravity ◽  
Global Navigation Satellite ◽  
Measuring Unit ◽  
Rough Sea

The strapdown gravimetry system uses the combination of an Inertial Measuring Unit (IMU) and a Global Navigation Satellite System (GNSS) to measure the Earth’s gravity field. Due to limited accuracies of IMU and GNSS, early strapdown gravimetry systems were more often used in airborne surveys, but less used in marine surveys. We developed a strapdown inertial navigation system (SINS), the Sea-Air Gravimeter-2Marine (SAG-2M), using novel IMU components, whose accuracy was further improved with the application of Precise Point Positioning (PPP) and enhanced algorithm, making it possible to be used in marine gravity survey. The testing results of the SAG-2M were compared to those of the Lacoste and Romberg S-129 gravimeter on the same ship in the South China Sea basin. The cruise lasted for 50 days, during which 134 effective gravity profiles were measured, resulting in 174 crossover points. The results showed that, for the SAG-2M, the root mean square (RMS) crossover points were 1.35 mGal before difference adjustment and 0.69 mGal after difference adjustment; for the S-129 gravimeter, they were 5.62 mGal and 0.95 mGal, correspondingly. In calm sea conditions, the results of the two systems were relatively consistent at all wavelengths. However, in rough sea conditions, since the SAG-2M was not affected by the cross-coupling effect, its data demonstrated less high-frequency jump. A physical platform adopted in SAG-2M can further make the transition data effective when the ship is turning around. Therefore, SAG-2M was able to improve the proportion of valid data and the efficiency of data post-processing for measurements taken during the cruise. The testing results indicate that in terms of accuracy and efficiency in the marine gravity survey, SAG-2M is better than S-129. In addition, as the miniaturization and precision of inertial components are developing continuously, SAG-2M also shows great potential in miniaturization.

scholarly journals Design of a Microcontroller Based System to Implement 4-Electode Focused Impedance Method (FIM)

2013 ◽  
Vol 4 (1) ◽  
pp. 75-79
Author(s):  
Dr Aktharuzzaman ◽  
Tanvir N Baig ◽  
K Siddique-e Rabbani
Keyword(s):  
Measurement System ◽  
Medical Physics ◽  
Impedance Measurement ◽  
Simulation Software ◽  
Signal Generator ◽  
Constant Current ◽  
Impedance Method ◽  
Electronic Circuitry ◽  
Measuring Unit

Designing of electronic circuitry and development of necessary software has been performed in the present work for a microcontroller based 4-electrode Focused Impedance measurement system. This needs a complex sequential analog switching of constant current ac signal generator and a potential measuring unit to 4 electrodes on the object under study. The performances of the designed system and the developed microcontroller software have been studied using a commercially available simulation software, ‘Proteus-7’, and the results are very satisfactory. DOI: http://dx.doi.org/10.3329/bjmp.v4i1.14690 Bangladesh Journal of Medical Physics Vol.4 No.1 2011 75-79

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