A measurement method for reflection coefficient of anechoic chamber using standing wave techniques

2003 ◽  
Author(s):  
B. Aswoyo ◽  
O. Makino ◽  
Y. Shimoshio ◽  
M. Tokuda
Keyword(s):  
Reflection Coefficient ◽  
Standing Wave ◽  
Measurement Method ◽  
Anechoic Chamber

An ultrasonic measurement method for full range of oil film thickness

2018 ◽  
Vol 233 (3) ◽  
pp. 481-489 ◽  
Author(s):  
Kai Zhang ◽  
Pan Dou ◽  
Tonghai Wu ◽  
Kai Feng ◽  
Youquan Zhu
Keyword(s):  
Reflection Coefficient ◽  
Film Thickness ◽  
Measurement Method ◽  
Ultrasonic Method ◽  
Dead Zone ◽  
Full Range ◽  
Thickness Measurement ◽  
Ultrasonic Measurement ◽  
Center Frequency ◽  
Oil Film

Ultrasonic method is quite promising for oil film thickness measurement in industry, while there is normally a dead zone for one ultrasonic sensor with a special center frequency when measuring the oil film thickness by the traditional reflection coefficient amplitude. In this paper, an ultrasonic measurement method for full range of oil film thickness was investigated. The theoretical relationship between the oil film thickness and the reflection coefficient phase was firstly built up and the reflection coefficient phase was found to be able to measure the oil film thickness in the dead zone. Then the reflection coefficient amplitude and phase were combined to measure the oil film thickness in the full range. A high-precision calibrated rig, which could form a series of known film thicknesses oil layers, was set up and the performance of this method was shown to work well. This method is significant for online oil film thickness monitoring in industry.

Theoretical research and experimental study for a new measurement method of standing wave levitation force

2015 ◽  
Vol 29 (5) ◽  
pp. 2169-2175 ◽  
Author(s):  
Xinbo Li ◽  
Hai Jiang ◽  
Xiaoyang Jiao ◽  
Kai Zhang ◽  
Guojun Liu ◽  
...  
Keyword(s):  
Experimental Study ◽  
Standing Wave ◽  
Measurement Method ◽  
Levitation Force ◽  
Theoretical Research

scholarly journals Novel Flexible Artificial Magnetic Conductor

2012 ◽  
Vol 2012 ◽  
pp. 1-7 ◽  
Author(s):  
M. E. de Cos ◽  
F. Las-Heras
Keyword(s):  
Reflection Coefficient ◽  
Oblique Incidence ◽  
Stability Margin ◽  
Laser Micromachining ◽  
Anechoic Chamber ◽  
Angular Stability ◽  
Polarization Angle ◽  
Magnetic Conductor ◽  
Artificial Magnetic Conductor

A novel flexible uniplanar AMC design is presented. An AMC prototype is manufactured using laser micromachining and it is characterized under flat and bent conditions by measuring its reflection coefficient phase in an anechoic chamber. The designed prototype shows broad AMC operation bandwidth (6.96% and higher) and polarization angle independency. Its angular stability margin, when operating under oblique incidence, is also tested obtaining±8°as limit for a 14.4 cm × 14.4 cm prototype.

Application of self-reciprocity in estimating ultrasonic power with a novel measurement method

Sensor Review ◽  
2014 ◽  
Vol 34 (4) ◽  
pp. 410-415 ◽  
Author(s):  
Ping Yang ◽  
Guangzhen Xing
Keyword(s):  
Reflection Coefficient ◽  
Measurement Method ◽  
Radiation Force ◽  
Open Circuit ◽  
Force Balance ◽  
Power Measurement ◽  
Ultrasonic Power ◽  
Content Type ◽  
Radiation Force Balance ◽  
Power Measurements

Purpose – This article aims to propose a new measurement method for ultrasonic power based on self-reciprocity theorem which turns the estimation of ultrasonic power to the measurement of first echo current and open-circuit voltage of the driving source. Design/methodology/approach – The formula for ultrasonic power is derived which has corrected the position of pressure reflection coefficient on the interface of water and steel. The diffraction correction for focusing transducers is evaluated using numerical computation of the Rayleigh integral. One way to estimate the reflection coefficient of focusing beams on heterogeneous interface is also depicted. Findings – Comparison experiment with radiation force balance method demonstrates that ultrasonic power measurement using self-reciprocity is sound in theory and feasible in practice. Originality/value – It has a better capability of anti-environmental interference and, thus, can be extended to low-level and high-frequency power measurements.

scholarly journals Bi-Ellipse Microstripline Antenna Array Varians

2021 ◽  
Author(s):  
Putu Artawan
Keyword(s):  
Reflection Coefficient ◽  
Antenna Array ◽  
Standing Wave ◽  
Microstrip Antenna ◽  
Communication Systems ◽  
Return Loss ◽  
Voltage Standing Wave Ratio ◽  
Frequency Range ◽  
X Band ◽  
Working Frequency

The objectives of this research include obtaining and verifying the impedance formula of the designed bi-ellipse microstrip antenna and correlating the results obtained through simulation and experimentation. The research also aims to obtain the structure and dimensions that provide optimal characteristics of the designed bi-ellipse microstrip antenna and produce a prototype at S, C and X-Band frequencies. This research produced the structure and dimensions of a bi-ellipse microstrip antenna that provide optimal characteristics of antenna. The characteristics results of the antenna parameters in this research include a 8x2 array, with a bandwidth value of around 100.0 MHz obtained at a working frequency of 7.09GHz (7.04 GHz - 7.14 GHz), with a reflection coefficient value of 0.02, Voltage Standing Wave Ratio (VSWR) of 1.06, return loss of −30.00 dB and a gain of 7.30 dB. For the 8x4 array, a bandwidth value of approximately 210.0 MHz is obtained at a working frequency range of 2.85GHz, which ranges from 2.74GHz - 2.95GHz, with a reflection coefficient value of 0.04, Voltage Standing Wave Ratio (VSWR) of 1.09, return loss of −27.06 dB and a gain of 8.19 dB. The results presented above fulfill the indicators of good antenna characteristics parameters applicable to radar communication systems.

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