scholarly journals Improving the accuracy and metrological support of power meters in the frequency range from 37.5 to 178.6 GHz

Doklady BGUIR ◽  
2021 ◽  
Vol 19 (3) ◽  
pp. 81-88
Author(s):  
A. V. Gusinsky ◽  
M. M. Kasperovich ◽  
V. A. Bogush
Keyword(s):  
Mathematical Model ◽  
Metrological Support ◽  
Microwave Power ◽  
Frequency Range ◽  
Standard Equipment ◽  
Automated Measurements ◽  
Absorbed Power ◽  
Power Measurements ◽  
Reference Body ◽  
Manufacturing Stage

To satisfy the needs for metrological support of power measurements in the frequency range from 37.5 to 178.6 GHz, the device has been developed and designed for automated measurements, calibrations and verification  of  wattmeters  with high  accuracy  and  the  ability  to  adapt  to  various  types  of  devices  under investigation. This paper presents the composition, diagram andgeneral principle of the device. A description of the structure of isothermal calorimetric converters of autocompensation type with dry load and reference body, which are the basis of the device, is given. The implemented algorithms for converting and replacing microwave power with direct current power of the developed calorimetric wattmeters are presented. The measures taken at the manufacturing stage to minimize sources of measurement uncertainty are described. To assess the accuracy of  measuring  the  absorbed  power, a  mathematical  model  of  the  conversion  factor  has  been  compiled. Corrections  have  been  introduced into  this  mathematical  model  to  improve  the  measurement  accuracy  of  the reproducible  microwave  power.  The  obtained  basic  metrological  and  technical  characteristics  of  calorimetric wattmeters  and  comparison  equipment  of  the  device  are  presented.  The  obtained  metrological  and  technical characteristics correspond to the current level of standard equipment.

The working standard of the unit of power of electromagnetic waves in the frequency range from 37,5 to 220 GHz

2020 ◽  
pp. 53-58
Author(s):  
A. V. Koudelny ◽  
I. M. Malay ◽  
V. A. Perepelkin ◽  
I. P. Chirkov
Keyword(s):  
Microwave Power ◽  
Electromagnetic Waves ◽  
Primary Standard ◽  
The State ◽  
Frequency Range ◽  
Working Standard ◽  
Extended Frequency Range ◽  
Effective Efficiency ◽  
Extended Frequency ◽  
Good Agreement

The possibility of using bolometric converters of microwave power from the State primary standard of the unit of power of electromagnetic waves in waveguide and coaxial paths GET 167-2017, which has a frequency range from 37,5 to 78,33 GHz, in an extended frequency range up to 220 GHz, is shown. Studies of semiconductor bolometric converters of microwave power in an extended frequency range have confirmed good agreement and smooth frequency characteristics of the effective efficiency factor of the converters. Based on the research results, the State working standard of the unit of power of electromagnetic waves of 0,1–10 mW in the frequency range from 37,5 to 220 GHz 3.1.ZZT.0288.2018 was approved. The technical characteristics of the working standard of the unit of power of electromagnetic oscillations in an extended frequency range from 37,5 to 220 GHz are given.

Mismatch Errors in Microwave Power Measurements

1953 ◽  
Vol 41 (9) ◽  
pp. 1112-1119 ◽  
Author(s):  
R. Beatty ◽  
A. MacPherson
Keyword(s):  
Microwave Power ◽  
Power Measurements

scholarly journals Simulation study of the large-scale modification of the mid-latitude F-layer by HF radio waves with different powers

2012 ◽  
Vol 30 (8) ◽  
pp. 1213-1222 ◽  
Author(s):  
G. I. Mingaleva ◽  
V. S. Mingalev ◽  
O. V. Mingalev
Keyword(s):  
Mathematical Model ◽  
Simulation Study ◽  
High Power ◽  
Large Scale ◽  
Radio Waves ◽  
Effective Frequency ◽  
Heating Facility ◽  
Absorbed Power

Abstract. A mathematical model of the ionosphere, developed earlier, is applied to investigate the large-scale mid-latitude F-layer modification by HF radio waves with different powers. Simulations are performed for the point with geographic coordinates of the "Sura" heating facility (Nizhny Novgorod, Russia) for autumn conditions. The calculations are made for distinct cases, in which the effective absorbed power has different values belonging to the 5–100 MW range, both for nocturnal and daytime conditions. The frequency of powerful HF waves is chosen to be close to the most effective frequency for the large-scale F2-layer modification. The results of modeling indicate that the effective absorbed power can influence considerably the F-layer response to high-power radio waves in the mid-latitude ionosphere.

Evaluation of Microbiological Safety of Shrimp Cooked in a Microwave Oven

1995 ◽  
Vol 58 (7) ◽  
pp. 742-747 ◽  
Author(s):  
SRIKANTH GUNDAVARAPU ◽  
YEN-CON HUNG ◽  
ROBERT E. BRACKETT ◽  
P. MALLIKARJUNAN
Keyword(s):  
Mathematical Model ◽  
Listeria Monocytogenes ◽  
Heat Resistance ◽  
Constant Temperature ◽  
Microwave Power ◽  
Thermal Inactivation ◽  
Microwave Oven ◽  
D Values ◽  
Cooking Times ◽  
Temperature Water

The effect of different microwave power levels (240, 400, 560, and 800 W) on the survival of Listeria monocytogenes in inoculated shrimp was investigated. Thermal inactivation rates (D-values) of L. monocytogenes were determined using constant temperature water baths to establish the heat resistance of L. monocytogenes in shrimp. Shrimp were inoculated with approximately 5 × 105 CFU/g of a five-strain mixture of L. monocytogenes. One hundred grams of shrimp were cooked in the microwave oven at different power levels using cooking times predicted by a mathematical model as well as 20% longer times than those obtained from the model. No viable L. monocytogenes were detected in uninoculated shrimp after microwave cooking, but at least one replication of inoculated shrimp tested positive for the presence of Listeria. No viable L. monocytogenes were detected in shrimp cooked at 120% of predicted times.

Metrological support to power measurements in the millimeter range

1975 ◽  
Vol 18 (9) ◽  
pp. 1357-1358
Author(s):  
A. N. Akhiezer ◽  
A. P. Sen'ko
Keyword(s):  
Metrological Support ◽  
Power Measurements

The Behaviour of Railway Wheelsets and Track at High Frequencies of Excitation

1982 ◽  
Vol 24 (2) ◽  
pp. 103-111 ◽  
Author(s):  
S. L. Grassie ◽  
R. W. Gregory ◽  
K. L. Johnson
Keyword(s):  
Experimental Data ◽  
Mathematical Model ◽  
Contact Force ◽  
Analytical Methods ◽  
Dynamical Response ◽  
Frequency Range ◽  
High Frequencies ◽  
Good Agreement

The dynamical response in the frequency range 50–1500 Hz is investigated of a railway wheelset resting on the track and excited vertically, laterally and longitudinally at a point of contact. A mathematical model of a railway wheelset is developed which comprises a few simple components to which analytical methods can be applied. Good agreement is obtained between experimental data and calculations made using this model. For a given sinusoidal displacement imposed between wheel and rail, the contact force is in general greatest longitudinally and least laterally.

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