scholarly journals Portable microwave radiometer for wearable devices

2021 ◽  
Vol 34 (04) ◽  
pp. 1431-1447
Author(s):  
Sergey G. Vesnin ◽  
Mikhail K. Sedankin ◽  
Lev M. Ovchinnikov ◽  
Alexander G. Gudkov ◽  
Vitaly Yu. Leushin ◽  
...  
Keyword(s):  
Measurement Error ◽  
Power Supply ◽  
Single Channel ◽  
Supply Voltage ◽  
Core Body Temperature ◽  
Microwave Radiometer ◽  
Wearable Devices ◽  
Design Stage ◽  
Usb Interface ◽  
Measurement Mode

This paper presents a new circuit of the miniature microwave radiometer for wearable devices, which can be used to monitor the core body temperature (CBT) of internal human tissues continuously 24/7. The measurement results of the proposed device, as opposed to the known miniature wearable radiometers, remain unchanged when the impedance of the examined area varies. We have derived an analytical expression for radiometer measurement error based on parameters of device components. This formula allows accuracies to be estimated and optimal parameters of the circuit to be selected to minimise measurement error at a design stage. It is shown that measurement error is independent of the antenna reflection coefficient and the temperature of the radiometer front-end. A prototype of the single-channel miniature radiometer has 32 х 25 х 14 mm3 dimensions and USB interface communication with PC. A 28-hour run of the device has shown that it is highly stable, and a maximum drift in temperature is 0.15 ̊C. Operating frequency range was 3400-4100 MHz, supply voltage - 5V; power supply of the radiometer in measurement mode is 210 mA; time constant of the radiometer without being averaged is 0.6 sec, at the same time, standard deviation δ = 0.17 ̊С, with further averaging during 4 sec δ=0.052 ̊С, with averaging during 30 sec δ =0.017 ̊C; when there were input reflections R2=0.25, an error in measuring brightness temperature shifted by 0.2 ̊ C; with 10 ̊C variations in ambient temperature the shift was 0.15 ̊C. Introduction of self-contained power supply and wireless communication with smartphone have made it possible to use the proposed radiometer as a wearable device to monitor the temperature of internal tissues and CBT during human activities.

Power Supply Voltage Dependence of Within-Die Delay Variation of Regular Manual Layout and Irregular Place-and-Route Layout

2011 ◽  
Vol E94-C (6) ◽  
pp. 1072-1075
Author(s):  
Tadashi YASUFUKU ◽  
Yasumi NAKAMURA ◽  
Zhe PIAO ◽  
Makoto TAKAMIYA ◽  
Takayasu SAKURAI
Keyword(s):  
Power Supply ◽  
Voltage Dependence ◽  
Supply Voltage ◽  
Power Supply Voltage ◽  
Place And Route ◽  
Delay Variation

Power Supply Voltage Control for Eliminating Overkills and Underkills in Delay Fault Testing

2016 ◽  
Vol E99.C (10) ◽  
pp. 1219-1225
Author(s):  
Masahiro ISHIDA ◽  
Toru NAKURA ◽  
Takashi KUSAKA ◽  
Satoshi KOMATSU ◽  
Kunihiro ASADA
Keyword(s):  
Power Supply ◽  
Supply Voltage ◽  
Voltage Control ◽  
Fault Testing ◽  
Power Supply Voltage ◽  
Delay Fault ◽  
Delay Fault Testing

AlInAs/GaInAs on InP HEMTs for low power supply voltage operation of high power-added efficiency microwave amplifiers

1993 ◽  
Vol 29 (15) ◽  
pp. 1324 ◽  
Author(s):  
L.E. Larson ◽  
M.M. Matloubian ◽  
J.J. Brown ◽  
A.S. Brown ◽  
M. Thompson ◽  
...  
Keyword(s):  
Low Power ◽  
High Power ◽  
Power Supply ◽  
Supply Voltage ◽  
Power Supply Voltage ◽  
Power Added Efficiency ◽  
Microwave Amplifiers

Experimental Study on the Emergency Ampacity of XLPE Cable and its Application

2014 ◽  
Vol 599-601 ◽  
pp. 931-934
Author(s):  
Xiao Liang Zhuang ◽  
Hai Qing Niu ◽  
Qun Feng Zhang ◽  
Kai Fa Ye ◽  
Guang Hui Sun
Keyword(s):  
Power Supply ◽  
Transmission Capacity ◽  
Design Stage ◽  
Initial Current ◽  
Xlpe Cable ◽  
Lifting Capacity ◽  
Increasing Demand ◽  
Line Design ◽  
The Relationship ◽  
New Distribution

In order to solve the contradiction between the increasing demand of power supplies and the difficulty of building new distribution lines, improving the transmission capacity of existing distribution cables is imperative. Using emergency ampacity can increase cable transmission capacity temporarily. Software of calculation emergency ampacity of distribution cable is developed and experiments are undertaken in this paper. The consistency of calculation and experiments shows that the software could calculate emergency ampacity of distribution cable correctly. By the software, the relationship between emergency ampacity and emergency time & initial status are studied here. The research shows that emergency ampacity is much higher than the continuous ampacity. What’s more, the shorter emergency time is, the higher emergency ampacity will be. The lower initial current is, the higher emergency ampacity will be. The more cable circuit number is, the lower emergency ampacity will be but the stronger lifting capacity will be. If emergency ampacity is considered in cable line design stage, cable cross-section or the number of circuit number could be reduced; and if emergency ampacity is considered in emergency load control, the number and capacity of transferring power supply can be reduced. The application the emergency ampacity of distribution cable will result in a great improvement in economy and reliability of power supply.

scholarly journals Analysis of Main LC-VCO Parameters for Multistandard Tranceivers

2017 ◽  
Vol 9 (3) ◽  
pp. 324-328 ◽  
Author(s):  
Vytautas Mačaitis ◽  
Romualdas Navickas
Keyword(s):  
Power Supply ◽  
Carrier Frequency ◽  
Power Dissipation ◽  
Figure Of Merit ◽  
Tuning Range ◽  
Supply Voltage ◽  
Quality Function ◽  
Voltage Controlled Oscillators ◽  
Cmos Ic ◽  
Ic Technology

This paper reviews CMOS LC Voltage Controlled Oscillators (VCO) for wireless multi-standard transceivers and wireless communications. The main parameters, such as IC technology, phase noise, carrier frequency, supply voltage, tuning range, power dissipation, figure of merit (FOMT and FOMTT) were reviewed in this paper. These parameters were taken of 20 articles published in 2012–2016 years. Of the reviewed articles it can be said that most VCOs was designed in 180 nm (55%) and 65 nm (25%) CMOS IC technology. FOMTT quality function has been proposed for extended VCO quality assessment. FOMTT quality function additionally evaluates VCO IC technology, and the power supply.

scholarly journals ELECTRIC SUPPLY OF UNDERGROUND CONSUMERS OF DEEP ENERGY-INTENSIVE MINES

2018 ◽  
pp. 25-46
Author(s):  
F. P. Shkrabets
Keyword(s):  
Power Supply ◽  
Supply Voltage ◽  
Maximum Load ◽  
Electrical Equipment ◽  
Transport Systems ◽  
Local Power ◽  
Electrical Networks ◽  
Electric Networks ◽  
Supply Networks ◽  
Technical And Economic Indicators

The increase in the capacity of cleaning and construction vehicles for highcapacity and energy-intensive mines calls for an increase in the  supply voltage of cleaning and tunneling combines, as well as  transport systems: from a voltage of 660 V switched to 1140 V, and  now to 3300 V. This allows improving technical and economic  indicators for clearing and access areas, as well as improving the reliability of local Power Supply Systems (PSS). However, this  trend prevents the supply of underground electric networks with a  voltage of 6 kV, in connection with which the problem arises of  increasing the voltage of supply networks. To date, it has become  possible to apply the 10 kV voltage to the operation, which is most  acceptable for the use of electrical equipment for electrical networks  and protection devices. Leading educational, research and design  organizations were engaged in research on this issue. An analysis of the results of the research showed that switching to 10 kV voltage is  justified and timely. At the same time, 35 kV voltage is not removed  from the agenda, which is technically feasible and economically  justified, but there are problems with the safety of its operation in  underground workings, which requires appropriate refinement. This  level of voltage will improve the quality of electricity.Conclusions: 1. Application of 35 kV voltage in the underground power supply system of coal and ore mines is advisable at a depth of more than 1000 m with a maximum load of at least 1000 kVA at the  level of the stem cables.2. Application of 35 kV voltage in underground electrical networks will allow to significantly improve the quality indicators of voltage,  reliability, and economy of the system due to the current unloading  of the most important element of SES, such as stem cables.3. Analysis of the main parameters and characteristics of electrical mine electrical equipment gives reason to believe that it allows  implementing a trend of 35 kV deep input to deep horizons of mines  (mines) and placement of 35/6 kV substations on working horizons.

Optimal Design of Energy-Saving Induction Cooker Power Controller Based on Fuzzy Technology

2014 ◽  
Vol 678 ◽  
pp. 423-428
Author(s):  
Pin Qi Zheng ◽  
Qing Sheng Yu
Keyword(s):  
Fuzzy Control ◽  
Output Power ◽  
Power Supply ◽  
Supply Voltage ◽  
Operating Temperature ◽  
Voltage Regulation ◽  
Soft Switching ◽  
Switch Mode ◽  
Output Efficiency ◽  
Switch Voltage

Application of Soft-switching technique and fuzzy control is discussed to optimize traditional induction cooker controller. Soft-switching technique is used to improve output efficiency of induction cooker. Switch voltage regulation by fuzzy control are used to adjust output power of induction cooker. Soft-switching inverter consists of resonant DC link and LC resonant network. Resonant DC link is used to realize ZVS, and resonant network is used to eliminate harmonics. Fuzzy control based on look-up table is adopted to adjust duty cycle of switch mode regulated power supply, which changes the DC supply voltage, so that amplitude of AC signal inverted by induction cooker is changed to adjust output power of induction cooker according to the requirement, , ensuring the operating temperature aligned with the target temperature.

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