Search results for "Amplifier"
showing 10 items of 239 documents
A continuous wave 10 W cryogenic fiber amplifier at 1015 nm and frequency quadrupling to 254 nm
2013
A stable, continuous wave, single frequency fiber amplifier system at 1015 nm with 10W output power is presented. It is based on a large mode double clad fiber cooled to liquid nitrogen temperature. The amplified light is frequency quadrupled to 254 nm and used for spectroscopy of the 6^1S - 6^3P transition in mercury.
Integrated Optical Amplifier-Photodetector on a Wearable Nanocellulose Substrate
2018
Flexible optoelectronics has emerged as an outstanding platform to pave the road toward vanguard technology advancements. As compared to conventional rigid substrates, a flexible technology enables mechanical deformation while maintaining stable performance. The advantages include not only the development to novel applications, but also the implementation of a wearable technology directly in contact with a curved surface. Here the monolithic integration of a perovskite‐based optical waveguide amplifier together with a photodetector on a nanocellulose substrate is shown to demonstrate the feasibility of a stretchable signal manipulation and receptor system fabricated on a biodegradable mater…
Novel GaN Based Solid State Power Amplifiers, Results, Advances and Comparison with Vacuum Tubes Based Microwave Power Modules
2018
Power amplifiers based on vacuum tubes or solid state are key items in a number of systems. Solid state technology is growing up for some applications and it may be complementary to the vacuum technology. This paperwork presents SSPA operational principles and performance. The GaN technology available in the market, the technology roadmap, a comparison with the vacuum tubes are introduced
Random telegraph signal transients in active logarithmic continuous-time vision sensors
2015
Abstract Random Telegraph Signal (RTS) is a well-known source of noise in current submicron circuits. Its static effects have been widely studied and its noise levels are in the order of other noise sources, especially for moderate submicron transistors. Nevertheless, RTS events may produce transients many times larger than the RTS itself, and this problem seems to have not yet been addressed. In this article we present results on the transients produced by RTS events in a smart vision sensor. RTS transients in closed-loop amplifiers can be many times greater than static RTS. The duration of the RTS transient may last for several milliseconds, and can be considered almost stationary for som…
A window amplitude discriminator with adjustable upper and lower thresholds
1976
An amplitude window discriminator is described which permits selection of spikes from a multi-unit recording, provided the signal-to-noise ratio is high enough. The device can be built at relatively low cost and time. The circuitry permits analysis of the positive or the negative deflections of the recorded signals. In Part One of the circuitry, the signals are pre-amplified and may be inverted in polarity. In Part Two, the pulses are compared to a variable lower threshold voltage, and low amplitude noise is eliminated. Part Three depicts a logic circuit for elimination of disturbing high-amplitude signals, whose output delivers digital pulses, each corresponding to an original signal (e.g.…
Noise Figures of Merit of rf-SQUID-based Josephson Travelling Wave Parametric Amplifiers
2021
The characterization of the rf-SQUID-based JTWPA in terms of its noise figure and gain for different input states (Fock states or Coherent states) has been carried out. The spectral distribution of the noise temperature Tn and gain G presents a region where the amplifier has a relatively high gain with a thermal noise that can go beyond the standard quantum limit =ℏ/2 (valid only for single mode input states [44]) as shown in Fig. 3. The TWJPA is here biased in its 3WM regime and pumped at p = 12 GHz.
Advanced PSA Bipolar Transistors for Wireless Applications: Measurements of Scattering Parameters and Noise Figure
1994
A complete investigation on the performance of a series of double polysilicon self-aligned (PSA) bipolar transistors in terms of scattering parameters and noise figure is here reported. The devices have been characterized over the 1-4 GHz frequency range in several bias conditions to the aim of assessing the optimum bias values for the best trade-off between noise and gain performance. This is the first part of an extensive investigation currently performed on 5 families of PSA devices having different emitter configuration and size which have been manufactured by SGS-Thomson to undergo a comparative analysis on the global transistor performance.
Influence Of The Model Parameters On The Noise Performance Of Double-polysilicon BJTs For Microwave LNA's
1997
In the recent post we have measured the noise and the scattering parameters of several series of double polysilicon BJT's over the 2-6 GHz frequency range at different collector current values, according to their emitter finger number. From the experimental data, a noisy circuit model has been extracted based on a T-equivalent network. By means of the correlation matrix techniques, novel analytical expressions of the noise parameters have been derived. As a second step, a sensitivity analysis has been performed for evaluating the influence of each model element on the noise performance. The results show how to improve the characteristics of such devices for a better performance when employe…
ACCURATE MEASUREMENTS OF OPTIMUM NOISE PARAMETERS OF MICROWAVE TRANSISTORS
1986
A method for measuring losses of the tuner network used as noise source admittance transformer in transistor noise parameter test-set is presented. Since the method is based on noise figure measurements, tuner losses can be determined on-line while performing measurements for determining transistor noise parameters. As experimental verifications the optimum noise parameters of a GaAs FET in the 4 - 12 GHz frequency range, measured through a computer-assisted measuring system, are reported.
Fast and efficient procedures for determining the microwave noise parameters of HEMT's at decreasing temperatures
1998
Noise parameters are an electrical representation of the noise performance of transistors which is widely used in reliability studies as well as in the design of low-noise microwave amplifiers. Such parameters are usually determined by employing a complex indirect (standard) procedure based on multiple noise figure measurements and appropriate data processing techniques. We report here two altemative and rapid methods used to perform the complete noise characterization of HEMT's at decreasing temperatures over the 6 to 18 GHz frequency range. The results show a very satisfactory agreement.among the different procedures thus assessing the inherent consistency of the global approach to the pr…