scholarly journals Solid state radio-measuring optical-frequency transducer of gas flow rate

2021 ◽  
Vol 22 (2) ◽  
pp. 224-232
Author(s):  
A.V. Osadchuk ◽  
V.S. Osadchuk ◽  
I.A. Osadchuk ◽  
D.R. Ilchuk ◽  
G.A. Pastushenko
Keyword(s):  
Solid State ◽  
Negative Differential Resistance ◽  
Gas Flow ◽  
Supply Voltage ◽  
Experimental Studies ◽  
Differential Resistance ◽  
Optical Frequency ◽  
Transistor Structure ◽  
Radio Measuring ◽  
Gas Consumption

The paper presents a study of a solid state radio-measuring optical-frequency transducer of gas consumption based on a transistor structure with a negative differential resistance. A mathematical model of a solid state radio-measuring optical-frequency flowmeter was developed, which made it possible to obtain the conversion function and the sensitivity equation. The solid state radio-measuring optical-frequency gas flowmeter is based on a transistor structure with a negative differential resistance, consisting of a HEMT field-effect transistor and a bipolar transistor with a passive inductive element. When replacing the passive inductance with an active inductive element, the transducer can be completely integrated. The negative differential resistance formed by the parallel connection of the impedance with the capacitive component on the collector-drain electrodes of the transistor structure and inductance leads to the occurrence of electrical oscillations in the oscillator circuit. Theoretical and experimental studies have shown that with an increase in gas consumption from 0 l/h to 4 l/h, the generation frequency decreases from 812.65 MHz to 811.62 MHz at a supply voltage of 3.3 V, and at a supply voltage of 3.8 V from 813.00 MHz to 811.80 MHz. It is shown that by choosing a constant voltage power supply mode, it is possible to obtain an almost linear dependence of the generation frequency on the gas flow rate and choose channels for transmitting measurement information. The obtained theoretical and experimental studies are in good agreement, the relative error does not exceed 2.5 %.

Optical-frequency gas flow meter on the basis of transistor structures with negative differential resistance

2020 ◽  
Author(s):  
Alexander V. Osadchuk ◽  
Volodymyr S. Osadchuk ◽  
Iaroslav O. Osadchuk ◽  
Nataliia V. Titova ◽  
Olga Y. Pinaeva ◽  
...  
Keyword(s):  
Negative Differential Resistance ◽  
Gas Flow ◽  
Differential Resistance ◽  
Optical Frequency ◽  
Flow Meter

Experimental Studies of New GaAs Metal/Insulator/p-n+Switches Using Low Temperature Oxide

2002 ◽  
Vol 25 (3) ◽  
pp. 233-237
Author(s):  
K. F. Yarn
Keyword(s):  
Low Temperature ◽  
Negative Differential Resistance ◽  
Doping Concentration ◽  
Experimental Studies ◽  
Differential Resistance ◽  
Switching Behavior ◽  
Metal Insulator ◽  
Turn On ◽  
Temperature Oxide ◽  
Phase Chemical

First observation of switching behavior is reported in GaAs metal-insulator-p-n+structure, where the thin insulator is grown at low temperature by a liquid phase chemical-enhanced oxide (LPECO) with a thickness of 100 Å. A significant S-shaped negative differential resistance (NDR) is shown to occur that originates from the regenerative feedback in a tunnel metal/insulator/semiconductor (MIS) interface andp-n+junction. The influence of epitaxial doping concentration on the switching and holding voltages is investigated. The switching voltages are found to be decreased when increasing the epitaxial doping concentration, while the holding voltages are almost kept constant. A high turn-off/turn-on resistance ratio up to105has been obtained.

Experimental Studies and Physical Model of Efficient, Tunable Injection Using Tunnel-Transparent Dielectric Contacts on Polymer Light-Emitting Devices

2002 ◽  
Vol 734 ◽  
Author(s):  
Ludmila Bakueva ◽  
Sergei Musikhin ◽  
Edward H. Sargent ◽  
Alexander Shik
Keyword(s):  
Dielectric Layer ◽  
Negative Differential Resistance ◽  
Voltage Drop ◽  
Strong Dependence ◽  
Experimental Studies ◽  
Differential Resistance ◽  
Hot Electron ◽  
Injection Efficiency ◽  
Light Emitting ◽  
Light Emitting Devices

ABSTRACTMost conducting polymers used for light-emitting devices have a small electron affinity, creating a high barrier for electron injection resulting in low injection efficiency. To improve injection characteristics, we fabricated and investigated multi-layer contacts with a tunneltransparent dielectric layer of nanometer thickness. Polymer layers were prepared by spin coating, and dielectric and metallic contact layers subsequently grown by vacuum deposition. Samples with such multi-layer cathodes demonstrated a current-voltage characteristic with negative differential resistance. At larger applied voltage, electroluminescence was observed with an efficiency larger than for a simple cathode of the same metal. We have developed a model to describe double injection through multi-layer contacts which explains these salient observed features. The increase in injection efficiency is caused by the voltage drop at the dielectric layer, shifting the metal Fermi level relative to the polymer molecular orbitals responsible for carrier transport. The negative differential resistance is explained by the strong dependence of dielectric tunnel transparency on voltage, a dependence which is qualitatively different for electrons and holes. Further flexibility in the functional characteristics of the injecting contacts is achieved through the use of an additional thin metallic layer playing the role of a base electrode, similar to hot-electron transistors with metallic base.

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