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1

FET input voltage amplifier for low frequency noise measurements

Achtenberg Krzysztof, Mikołajczyk Janusz, Bielecki Zbigniew

Metrology and Measurement Systems

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2020

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Vol. 27, nr 3

531--540

EN

The paper presents a low noise voltage FET amplifier for low frequency noise measurements. It was built using two stages of an op amp trans impedance amplifier. To reduce voltage noise, eight-paralleled low noise discrete JFETs were used in the first stage. The designed amplifier was then compared to commercial ones. Its measured value of voltage noise spectral density is around 24 nV/√Hz, 3 nV/√Hz, 0.95 nV/√Hz and 0.6 nV/√Hz at the frequency of 0.1, 1, 10 and 100 Hz, respectively. A -3dB frequency response is from ~20 mHz to ~600 kHz.

2

Transistor Effect in the Cochlear Amplifier

Kiełczyński P., Szalewski M.

Archives of Acoustics

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2014

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Vol. 39, No. 1

117--124

EN

The paper presents a new electromechanical amplifying device i.e., an electromechanical biological transistor. This device is located in the outer hair cell (OHC), and constitutes a part of the Cochlear amplifier. The physical principle of operation of this new amplifying device is based on the phenomenon of forward mechanoelectrical transduction that occurs in the OHC’s stereocilia. Operation of this device is similar to that of classical electronic Field Effect Transistor (FET). In the considered electromechanical transistor the input signal is a mechanical (acoustic) signal. Whereas the output signal is an electric signal. It has been shown that the proposed electromechanical transistor can play a role of the active electromechanical controlled element that has the ability to amplify the power of input AC signals. The power required to amplify the input signals is extracted from a battery of DC voltage. In the considered electromechanical transistor, that operates in the amplifier circuit, mechanical input signal controls the flow of electric energy in the output circuit, from a battery of DC voltage to the load resistance. Small signal equivalent electrical circuit of the electromechanical transistor is developed. Numerical values of the electrical parameters of the equivalent circuit were evaluated. The range, which covers the levels of input signals (force and velocity) and output signals (voltage, current) was determined. The obtained data are consistent with physiological data. Exemplary numerical values of currents, voltages, forces, vibrational velocities and power gain (for the assumed input power levels below 1 picowatt (〖10〗^(-12) W), were given. This new electromechanical active device (transistor) can be responsible for power amplification in the cochlear amplifier in the inner ear.

3

Field effect transistors for terahertz detection : silicon versus III-V material issue

Knap W., Videlier H., Nadar S., Coquillat D., Dyakonova N., Teppe F., Bialek M., Grynberg M., Karpierz K., Lusakowski J., Nogajewski K., Seliuta D., Kašalynas I., Valušis G.

Opto-Electronics Review

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2010

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Vol. 18, No. 3

225-230

EN

Resonant frequencies of the two-dimensional plasma in FETs reach the THz range for nanometer transistor channels. Non-linear properties of the electron plasma are responsible for detection of THz radiation with FETs. Resonant excitation of plasma waves with sub-THz and THz radiation was demonstrated for short gate transistors at cryogenic temperatures. At room temperature, plasma oscillations are usually over-damped, but the FETs can still operate as efficient broadband THz detectors. The paper presents the main theoretical and experimental results on detection with FETs stressing their possible THz imaging applications. We discuss advantages and disadvantages of application of III-V GaAs and GaN HEMTs and silicon MOSFETs.

4

Femtoamperomierze elektroniczne

Wiśniewski J.

Elektronika : konstrukcje, technologie, zastosowania

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2010

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Vol. 51, nr 9

158-160

PL

W pracy przedstawiono - zaproponowane przez autora - układy femtoamperomierzy elektronicznych wykorzystujących zjawisko ładowania wzorcowego kondensatora styrofleksowego prądem stałym. Układy te cechują się dużą czułością i umożliwiają pomiar prądu stałego w zakresie 10 fA ÷ 100 nA. O ich zaletach stanowi również prosta budowa, wysoka ekonomia zasilania, łatwa odtwarzalność i niska cena. Z tych względów mogą one znaleźć szerokie zastosowanie w wielu studenckich i przemysłowych elektronicznych laboratoriach badawczych a także w domowym laboratorium każdego elektronika do badania unikalnych właściwości podstawowych przyrządów półprzewodnikowych.

EN

In this article it has been described - proposed by author - two circuits of electronic femtoammeters which are based on phenomena of charging fixed dielectric (polystyrene) film capacitor by direct current (DC). These circuits characterize high sensitivity and enable measurement DC current from 10 fA to 100 nA. Others advantages include: simple structures, high economy of power supply, easy reproducing and Iow cost. Because of above - mentioned features these ammeters can be applied in wide range of applications in many electronic laboratories (also student's) to research and exploration unique properties of essentials semiconductor devices.

5

Mikroelektroniczne i optoelektroniczne przyrządy sensorowe z warstwami diamentowymi i diamentopodobnymi

Śmietana M., Werbowy A., Szmidt J.

Elektronika : konstrukcje, technologie, zastosowania

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2008

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Vol. 49, nr 9

126-130

PL

Praca przedstawia badania nad możliwością dostosowania technologii wytwarzania czujnikowych struktur mikroelektronicznych i optoelektronicznych do specyficznych wymagań narzucanych przez procesy osadzania warstw diamentowych i diamentopodobnych. Opracowano i zrealizowano złożone procesy technologiczne przygotowania podłoży, a także osadzania i trawienia warstw węglowych, co dało możliwość wytworzenia czujnikowych struktur światłowodowych oraz tranzystorów FET z otwartą bramką. Dowiedziono, iż w przypadku czujników światłowodowych warstwy diamentopodobne mogą wielokrotnie zwiększać czułość wytworzonych przyrządów na zmiany koncentracji związków chemicznych w roztworach wodnych.

EN

Work presents researches on adaptation of microelectronic and optoelectronic sensing structures technology to specific requirements imposed by deposition processes of diamond and diamond-like carbon films. There were developed complex technological processes of substrates preparation, as well as deposition and processing of carbon films, in order to fabricate fibre optic sensing structures (e.g. long-period gratings) and also microelectronic open-gate field effect transistors. It was proven that in case of fibre optic sensors diamond-like carbon film overlay can multiple their sensitivity to variations of concentration of chemical compounds in water solutions.