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M J W Rodwell - One of the best experts on this subject based on the ideXlab platform.
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mm wave op amps for low distortion amplification with high oip3 p dc ratio 100 at 2 ghz
International Conference on Indium Phosphide and Related Materials, 2008Co-Authors: Z Griffith, M Urteaga, M J W RodwellAbstract:We here report mm-wave amplifiers employing strong Global Negative Feedback to provide very low intermodulation distortion, using an InP DHBT technology. The amplifiers, similar to operational amplifiers, use simple- or nested-Miller compensation and have 25 to 40 GHz Feedback loop bandwidths. The large loop transmission at 2 GHz provides a large reduction of closed-loop distortion at this frequency. A simple-compensated amplifier with 24.8 GHz bandwidth and having 1013 mW dissipation showed 13.8 dB (S21) gain and 50.2 dBm OIP3 at (1.950, 1.975 GHz). It is unconditionally stable from DC to 15 GHz, and stable in a 50 Omega system from DC to 50 GHz. A nested-compensated amplifier with 40 GHz bandwidth and having 993 mW dissipation showed 13.8 dB (S21) gain and 42.8 dBm OIP3 at (1.950, 1.975 GHz). It is unconditionally stable from DC-20 GHz and stable in a 50 Omega system from DC to 50 GHz. These results represent ~ 4times increase in bandwidth for an op-amp of any kind, as well as ~ 3times betterment in OIP3/PDC ratio at fs = 2-3 GHz, when compared to state-of-the-art. We address considerations important to the application of Negative Feedback to mm-, microwave amplifiers, including the effects of interface impedances on stability, the effect of Feedback upon return losses and noise figure, and the effect of frequency compensation and of Feedback topology on closed-loop distortion.
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mm-wave op-amps for low distortion amplification with high OIP3/P DC ratio ≫ 100 at 2 GHz
2008 20th International Conference on Indium Phosphide and Related Materials, 2008Co-Authors: Z Griffith, M Urteaga, M J W RodwellAbstract:We here report mm-wave amplifiers employing strong Global Negative Feedback to provide very low intermodulation distortion, using an InP DHBT technology. The amplifiers, similar to operational amplifiers, use simple- or nested-Miller compensation and have 25 to 40 GHz Feedback loop bandwidths. The large loop transmission at 2 GHz provides a large reduction of closed-loop distortion at this frequency. A simple-compensated amplifier with 24.8 GHz bandwidth and having 1013 mW dissipation showed 13.8 dB (S21) gain and 50.2 dBm OIP3 at (1.950, 1.975 GHz). It is unconditionally stable from DC to 15 GHz, and stable in a 50 Omega system from DC to 50 GHz. A nested-compensated amplifier with 40 GHz bandwidth and having 993 mW dissipation showed 13.8 dB (S21) gain and 42.8 dBm OIP3 at (1.950, 1.975 GHz). It is unconditionally stable from DC-20 GHz and stable in a 50 Omega system from DC to 50 GHz. These results represent ~ 4times increase in bandwidth for an op-amp of any kind, as well as ~ 3times betterment in OIP3/PDC ratio at fs = 2-3 GHz, when compared to state-of-the-art. We address considerations important to the application of Negative Feedback to mm-, microwave amplifiers, including the effects of interface impedances on stability, the effect of Feedback upon return losses and noise figure, and the effect of frequency compensation and of Feedback topology on closed-loop distortion.
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mm-Wave Op-Amps Employing Simple-Miller Compensation, with OIP3/Pdc Ratios of 211 (10dB NF) and 144 (6.0dB NF) at 2 GHz
2008 IEEE Compound Semiconductor Integrated Circuits Symposium, 2008Co-Authors: Z Griffith, M Urteaga, M J W RodwellAbstract:We here report two mm-wave amplifiers employing strong Global Negative Feedback to provide very low intermodulation distortion, using a 500 nm InP DHBT technology. The amplifiers, similar to operational amplifiers, use simple-Miller compensation and have 25 to 35 GHz Feedback loop bandwidths. The large loop transmission at 2 GHz provides a large reduction of closed-loop distortion at this frequency. The first amplifier, designed for lowest IM3 distortion at this technology node, showed 35 GHz bandwidth, 13.8 dB (S21) gain, with 1005 mW dissipation - where 53.2 dBm OIP3 and 10 dB NF are observed at f1, f2 = 1.950, 1.975 GHz. It is unconditionally stable from DC to 15 GHz. The second amplifier improves upon noise figure through less-strong Feedback and minimal input padding resistance, showing 25.8 GHz bandwidth, 19.8 dB (S21) gain, with 956 mW dissipation - where 51.4 dBm OIP3 and 6 dB NF are observed at f1, f2 = 1.950, 1.975 GHz. It is unconditionally stable from DC to 8 GHz. These results represent a ~ 1.4 x bandwidth increase for an op-amp employing simple-Miller compensation, as well as ~ 2.0 and 1.4 x betterment in OIP3/Pdc ratio at fs = 2-3 GHz, compared to state-of-the-art. We address considerations important to the application of Negative Feedback to mm-, microwave amplifiers, including the effects of interface impedances on stability, the effect of Feedback upon return losses and noise figure, and the effect of frequency compensation and of Feedback topology on closed-loop distortion.
Z Griffith - One of the best experts on this subject based on the ideXlab platform.
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mm wave op amps for low distortion amplification with high oip3 p dc ratio 100 at 2 ghz
International Conference on Indium Phosphide and Related Materials, 2008Co-Authors: Z Griffith, M Urteaga, M J W RodwellAbstract:We here report mm-wave amplifiers employing strong Global Negative Feedback to provide very low intermodulation distortion, using an InP DHBT technology. The amplifiers, similar to operational amplifiers, use simple- or nested-Miller compensation and have 25 to 40 GHz Feedback loop bandwidths. The large loop transmission at 2 GHz provides a large reduction of closed-loop distortion at this frequency. A simple-compensated amplifier with 24.8 GHz bandwidth and having 1013 mW dissipation showed 13.8 dB (S21) gain and 50.2 dBm OIP3 at (1.950, 1.975 GHz). It is unconditionally stable from DC to 15 GHz, and stable in a 50 Omega system from DC to 50 GHz. A nested-compensated amplifier with 40 GHz bandwidth and having 993 mW dissipation showed 13.8 dB (S21) gain and 42.8 dBm OIP3 at (1.950, 1.975 GHz). It is unconditionally stable from DC-20 GHz and stable in a 50 Omega system from DC to 50 GHz. These results represent ~ 4times increase in bandwidth for an op-amp of any kind, as well as ~ 3times betterment in OIP3/PDC ratio at fs = 2-3 GHz, when compared to state-of-the-art. We address considerations important to the application of Negative Feedback to mm-, microwave amplifiers, including the effects of interface impedances on stability, the effect of Feedback upon return losses and noise figure, and the effect of frequency compensation and of Feedback topology on closed-loop distortion.
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mm-wave op-amps for low distortion amplification with high OIP3/P DC ratio ≫ 100 at 2 GHz
2008 20th International Conference on Indium Phosphide and Related Materials, 2008Co-Authors: Z Griffith, M Urteaga, M J W RodwellAbstract:We here report mm-wave amplifiers employing strong Global Negative Feedback to provide very low intermodulation distortion, using an InP DHBT technology. The amplifiers, similar to operational amplifiers, use simple- or nested-Miller compensation and have 25 to 40 GHz Feedback loop bandwidths. The large loop transmission at 2 GHz provides a large reduction of closed-loop distortion at this frequency. A simple-compensated amplifier with 24.8 GHz bandwidth and having 1013 mW dissipation showed 13.8 dB (S21) gain and 50.2 dBm OIP3 at (1.950, 1.975 GHz). It is unconditionally stable from DC to 15 GHz, and stable in a 50 Omega system from DC to 50 GHz. A nested-compensated amplifier with 40 GHz bandwidth and having 993 mW dissipation showed 13.8 dB (S21) gain and 42.8 dBm OIP3 at (1.950, 1.975 GHz). It is unconditionally stable from DC-20 GHz and stable in a 50 Omega system from DC to 50 GHz. These results represent ~ 4times increase in bandwidth for an op-amp of any kind, as well as ~ 3times betterment in OIP3/PDC ratio at fs = 2-3 GHz, when compared to state-of-the-art. We address considerations important to the application of Negative Feedback to mm-, microwave amplifiers, including the effects of interface impedances on stability, the effect of Feedback upon return losses and noise figure, and the effect of frequency compensation and of Feedback topology on closed-loop distortion.
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mm-Wave Op-Amps Employing Simple-Miller Compensation, with OIP3/Pdc Ratios of 211 (10dB NF) and 144 (6.0dB NF) at 2 GHz
2008 IEEE Compound Semiconductor Integrated Circuits Symposium, 2008Co-Authors: Z Griffith, M Urteaga, M J W RodwellAbstract:We here report two mm-wave amplifiers employing strong Global Negative Feedback to provide very low intermodulation distortion, using a 500 nm InP DHBT technology. The amplifiers, similar to operational amplifiers, use simple-Miller compensation and have 25 to 35 GHz Feedback loop bandwidths. The large loop transmission at 2 GHz provides a large reduction of closed-loop distortion at this frequency. The first amplifier, designed for lowest IM3 distortion at this technology node, showed 35 GHz bandwidth, 13.8 dB (S21) gain, with 1005 mW dissipation - where 53.2 dBm OIP3 and 10 dB NF are observed at f1, f2 = 1.950, 1.975 GHz. It is unconditionally stable from DC to 15 GHz. The second amplifier improves upon noise figure through less-strong Feedback and minimal input padding resistance, showing 25.8 GHz bandwidth, 19.8 dB (S21) gain, with 956 mW dissipation - where 51.4 dBm OIP3 and 6 dB NF are observed at f1, f2 = 1.950, 1.975 GHz. It is unconditionally stable from DC to 8 GHz. These results represent a ~ 1.4 x bandwidth increase for an op-amp employing simple-Miller compensation, as well as ~ 2.0 and 1.4 x betterment in OIP3/Pdc ratio at fs = 2-3 GHz, compared to state-of-the-art. We address considerations important to the application of Negative Feedback to mm-, microwave amplifiers, including the effects of interface impedances on stability, the effect of Feedback upon return losses and noise figure, and the effect of frequency compensation and of Feedback topology on closed-loop distortion.
Irving R. Epstein - One of the best experts on this subject based on the ideXlab platform.
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A CANARD MECHANISM FOR LOCALIZATION IN SYSTEMS OF GlobalLY COUPLED OSCILLATORS
SIAM Journal on Applied Mathematics, 2003Co-Authors: Anatol M Zhabotinsky, Irving R. Epstein, Horacio G. Rotstein, Nancy KopellAbstract:Localization in a discrete system of oscillators refers to the partition of the population into a subset that oscillates at high amplitudes and anotherthat oscillates at much loweramplitudes. Motivated by experimental results on the Belousov-Zhabotinsky reaction, which oscillates in the relaxation regime, we study a mechanism of localization in a discrete system of relaxation oscillators Globally coupled via inhibition. The mechanism is based on the canard phenomenon for a single relaxation oscillator: a rapid explosion in the amplitude of the limit cycle as a parameter governing the relative position of the nullclines is varied. Starting from a parameter regime in which each uncoupled oscillatorhas a lar ge amplitude and no otherper iodic orotherstable solutions, we show that the canard phenomenon can be induced by increasing a Global Negative Feedback parameter γ, with the network then partitioned into low and high amplitude oscillators. For the case in which the oscillators are synchronous within each of the two such populations, we can assign a canard-inducing critical value of γ separately to each of the two clusters; localization occurs when the value for the system is between the critical values of the two clusters. We show that the larger the cluster size, the smaller is the corresponding critical value of γ, implying that it is the smallerclusterthat oscillates at large amplitude. The theory shows that the above results come from a kind of self-inhibition of each cluster induced by the local Feedback. In the full system, there are also effects of interactions between the clusters, and we present simulations showing that these nonlocal interactions do not destroy the localization created by the self-inhibition.
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oscillatory cluster patterns in a homogeneous chemical system with Global Feedback
Nature, 2000Co-Authors: Vladimir K. Vanag, Lingfa Yang, Milos Dolnik, Anatol M Zhabotinsky, Irving R. EpsteinAbstract:Oscillatory clusters are sets of domains in which nearly all elements in a given domain oscillate with the same amplitude and phase1,2,3,4. They play an important role in understanding coupled neuron systems5,6,7,8. In the simplest case, a system consists of two clusters that oscillate in antiphase and can each occupy multiple fixed spatial domains. Examples of cluster behaviour in extended chemical systems are rare, but have been shown to resemble standing waves9,10,11,12,13, except that they lack a characteristic wavelength. Here we report the observation of so-called ‘localized clusters’—periodic antiphase oscillations in one part of the medium, while the remainder appears uniform—in the Belousov–Zhabotinsky reaction–diffusion system with photochemical Global Feedback. We also observe standing clusters with fixed spatial domains that oscillate periodically in time and occupy the entire medium, and irregular clusters with no periodicity in either space or time, with standing clusters transforming into irregular clusters and then into localized clusters as the strength of the Global Negative Feedback is gradually increased. By incorporating the effects of Global Feedback into a model of the reaction, we are able to simulate successfully the experimental data.
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Pattern Formation in the Belousov−Zhabotinsky Reaction with Photochemical Global Feedback
The Journal of Physical Chemistry A, 2000Co-Authors: Vladimir K. Vanag, And Anatol M. Zhabotinsky, Irving R. EpsteinAbstract:We have found a variety of oscillating patterns in the Belousov−Zhabotinsky (BZ) reaction−diffusion system with Global Negative Feedback. Bulk oscillations and wave patterns arise at low values of the Feedback strength. When the Feedback exceeds a critical value, cluster patterns arise. Besides the standing, irregular, and localized clusters observed earlier, we have found new types of clusters: three-phase, localized irregular, and localized oscillatory clusters. A model of three identical Oregonators with Global Negative coupling yields the same bifurcation scenario as found in our experiments.
Bram Nauta - One of the best experts on this subject based on the ideXlab platform.
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wide band cmos low noise amplifier exploiting thermal noise canceling
IEEE Journal of Solid-state Circuits, 2004Co-Authors: F Bruccoleri, Eric A M Klumperink, Bram NautaAbstract:Known elementary wide-band amplifiers suffer from a fundamental tradeoff between noise figure (NF) and source impedance matching, which limits the NF to values typically above 3 dB. Global Negative Feedback can be used to break this tradeoff, however, at the price of potential instability. In contrast, this paper presents a feedforward noise-canceling technique, which allows for simultaneous noise and impedance matching, while canceling the noise and distortion contributions of the matching device. This allows for designing wide-band impedance-matching amplifiers with NF well below 3 dB, without suffering from instability issues. An amplifier realized in 0.25-/spl mu/m standard CMOS shows NF values below 2.4 dB over more than one decade of bandwidth (i.e., 150-2000 MHz) and below 2 dB over more than two octaves (i.e., 250-1100 MHz). Furthermore, the total voltage gain is 13.7 dB, the -3-dB bandwidth is from 2 MHz to 1.6 GHz, the IIP2 is +12 dBm, and the IIP3 is 0 dBm. The LNA drains 14 mA from a 2.5-V supply and the die area is 0.3/spl times/0.25 mm/sup 2/.
Vladimir K. Vanag - One of the best experts on this subject based on the ideXlab platform.
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Dynamics of a 1D array of inhibitory coupled chemical oscillators in microdroplets with Global Negative Feedback
Physical Chemistry Chemical Physics, 2018Co-Authors: Ivan S. Proskurkin, Vladimir K. VanagAbstract:We have investigated the effect of Global Negative Feedback (GNF) on the dynamics of a 1D array of water microdroplets (MDs) filled with the reagents of the photosensitive oscillatory Belousov–Zhabotinsky (BZ) reaction. GNF is established by homogeneous illumination of the 1D array with the light intensity proportional to the number of BZ droplets in the oxidized state with the coefficient of proportionality ge. MDs are immersed in the continuous oil phase and diffusively coupled with the neighboring droplets via inhibitor Br2 which is soluble in the oil phase. At chosen concentrations of the BZ reactants, illumination suppresses the BZ oscillators. Without GNF, or at a very small ge 4), in the region of two-phase clusters (with several suppressed BZ MDs), final patterns seem to resemble the initial patterns. Intensive computer simulations with the ordinary differential equations support experimental results.
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oscillatory cluster patterns in a homogeneous chemical system with Global Feedback
Nature, 2000Co-Authors: Vladimir K. Vanag, Lingfa Yang, Milos Dolnik, Anatol M Zhabotinsky, Irving R. EpsteinAbstract:Oscillatory clusters are sets of domains in which nearly all elements in a given domain oscillate with the same amplitude and phase1,2,3,4. They play an important role in understanding coupled neuron systems5,6,7,8. In the simplest case, a system consists of two clusters that oscillate in antiphase and can each occupy multiple fixed spatial domains. Examples of cluster behaviour in extended chemical systems are rare, but have been shown to resemble standing waves9,10,11,12,13, except that they lack a characteristic wavelength. Here we report the observation of so-called ‘localized clusters’—periodic antiphase oscillations in one part of the medium, while the remainder appears uniform—in the Belousov–Zhabotinsky reaction–diffusion system with photochemical Global Feedback. We also observe standing clusters with fixed spatial domains that oscillate periodically in time and occupy the entire medium, and irregular clusters with no periodicity in either space or time, with standing clusters transforming into irregular clusters and then into localized clusters as the strength of the Global Negative Feedback is gradually increased. By incorporating the effects of Global Feedback into a model of the reaction, we are able to simulate successfully the experimental data.
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Pattern Formation in the Belousov−Zhabotinsky Reaction with Photochemical Global Feedback
The Journal of Physical Chemistry A, 2000Co-Authors: Vladimir K. Vanag, And Anatol M. Zhabotinsky, Irving R. EpsteinAbstract:We have found a variety of oscillating patterns in the Belousov−Zhabotinsky (BZ) reaction−diffusion system with Global Negative Feedback. Bulk oscillations and wave patterns arise at low values of the Feedback strength. When the Feedback exceeds a critical value, cluster patterns arise. Besides the standing, irregular, and localized clusters observed earlier, we have found new types of clusters: three-phase, localized irregular, and localized oscillatory clusters. A model of three identical Oregonators with Global Negative coupling yields the same bifurcation scenario as found in our experiments.