Realization of Fully Differential Fourth-Order Bessel Filter with Accurate Group Delay

A fully differential R-MOSFET-C fourth-order Bessel active lowpass filter employing fully differential operational amplifier,passive resistors,and current-steering MOS transistors as a variable resistor is proposed.This proposed implementation relies on the tunability of current-steering MOS transistors operating in the triode region counteracting the concert deviation of resistor in the integrated circuit manufacturing technology in orde r that the group delay of Bessel active filter could be designed accurately.The amplifier is not only with voltage common-mode negative feedback,but also with current common-mode negative feedback,which will benefit for the stability of its D C operating point.0.75μs group delay fourth-order Bessel lowpass filter,whic h is synthesized according to passive doubly terminated RLC prototype lowpass filter,demonstrates better than -65dB THD using 100kHz,2.5V pp signal in Taiwan UMC 2P2M(2-poly,2-metal)5.0V,0.5μm CMOS technology.

Fully differential cross sections for C^(6+) single ionization of helium

The three-Coulomb-wave （3C） model is applied to study the single ionization of helium by 2 MeV/amu C6＋ impact. Fully differential cross sections （FDCS） are calculated in the scattering plane and the results are compared with experimental data and other theoretical predictions. It is shown that the 3C results of the recoil peak are in very good agreement with experimental observations, and variation of the position of the binary peak with increasing momentum transfer also conforms better to the experimental results. Furthermore, the contributions of different scat- tering amplitudes are discussed. It turns out that the cross sections are strongly influenced by the interference of these amplitudes.

Theoretical analysis on fully differential cross sections for C^(6+)impact ionization of helium

Fully differential cross sections （FDCS） are calculated within a four-body model for single ionization of helium by C6＋ impact at the incident energy of 100 MeV/a.u. （atomic unit）. The results are compared with experimental data and other theoretical predictions. It is shown that our results are in very good agreement with experiment for three small momentum transfers in the scattering plane; however, some significant discrepancies are still present at the largest momentum transfer in both the scattering plane and the perpendicular plane. In actuality, the problem has not been explained by the theory during the last decade. Accordingly, the contributions of different scattering amplitudes to FDCS are analyzed. It is found that for the largest momentum transfer the cross section arising from a destructive interference of the three amplitudes is much smaller than the experimental data. However, the cross section due to the constructive interference of two scattering amplitudes between projectile-ionized electron interaction and projectile-passive electron interaction almost approaches the experimental data.

Theoretical Analysis on Fully Differential Cross-Sections for C^6＋ Single Ionization of Helium

The four-body model has been used to calculate the fully differential cross-sections （FDCS） for the single ionization of helium by 100 MeV/amu Ca^＋ impact in geometries. By comparing with experimental data and other theories, we find the results of four-body model are in very good agreement in the scattering plane, but poor agreement out of the scattering plane. Accordingly, the contributions of different scattering amplitudes to FDCS are analyzed. It is found that the cross sections due to the interference of the scattering amplitudes between projectile-target nucleus interaction and projectile-ejected electron interaction almost tend to experimental results around the recoil region in geometries. In particular in the perpendicular plane, the cross section originating from interference of the scattering amplitudes between projectile-target nucleus and projectile-ejected electron interactions yields an experimental double-peak structure in the angular distribution. However, this feature could not be presented by the interference of the three amplitudes. Thus, the failure of the fourbody model predicting the feature in this geometry may be attributed to an inappropriate weighting of the three amplitudes.

Nucleus-Nucleus Effects in Fully Differential Cross Sections for Energetic C6++He Collisions with Small Momentum Transfer

The modified Coulomb-Born approximation with and without the internuclear interaction （MCB-NN and MCB） is used to calculate the fully differential cross sections （FDCS） for the single ionization of helium by lOO MeV/amu C6＋ impact. The effects of the internuclear interaction on the FDCS are examined in geometries. The results are compared with experimental data and theoretical predictions from a three-body distorted-wave （3DW） model and a time-dependent close-coupling model. It is shown that the present MCB-NN results are in good agreement with the experiments in the scattering plane and the MCB results qualitatively reproduce the experimental structure outside the scattering plane. In particular, the MCB theory predicts the ＇double-peak＇ structure in the perpendicular plane.

The effect of dynamical screening on helium(e,2e) fully differential cross-sections

This paper presents the fully differential cross sections （FDCS） for 102eV electron impact single ionization of helium for both the coplanar and perpendicular plane asymmetric geometries within the framework of dynamically screened three-Coulomb-wave theory. Comparisons are made with the experimental data and those of the three-Coulomb wave function model and second-order distorted-wave Born method. The angular distribution and relative heights of the present FDCS is found to be in very good agreement with the experimental data in the perpendicular plane geometry. It is shown that dynamical screening effects are significant in this geometry. Three-body coupling is expected to be weak in the coplanar geometry, although the precise absolute value of the cross section is still sensitive to the interaction details.

CNTFET Based Fully Differential First Order All Pass Filter

A novel,carbon nanotubefield effect transistor(CNTFET)based fully differentialfirst order all passfilter(FDFAPF)circuit configuration is presented.The FDFAPF uses CNTFET based negative transconductors(NTs)and positive transconductors(PTs)in its realization.The proposed circuit topology employs two PTs,two NTs,two resistors and one capacitor.All the passive components of the realized topology are grounded.Active only fully differentialfirst order all passfilter(AO-FDFAPF)topology is also derived from the proposed FDFAPF.The electronic tunability of the AO-FDFAPF is obtained by controlling the employed CNTFET based varactor.A tunabilty of pole frequency in the range of 10.5 to 26 GHz is obtained.Both the circuits are potential candidates for high frequency fully differential analog signal processing applications.As compared to prior state-of-the-art works,both the realized topologies have achieved highest pole frequency and lowest power dissipation.Moreover,they utilize compact circuit structures and suitable for low voltage applications.Moreover,both topologies work equally well in the deep submicron.The proposedfilters are analyzed and verified through HPSPICE simulations by utilizing Stanford CNTFET model at 16 nm technology node.It is observed that the proposed circuit simulation outcomes verify the theory.

Demonstration of a fully differential VGA chip with small THD for ECG acquisition system

We present both a theoretical and experimental demonstration of a fully differential variable gain am- plifier （VGA） with small total harmonic distortion （THD） for an electrocardiogram （ECG） acquisition system. Capacitive feedback technology is adopted to reduce the nonlinearity of VGA. The fully differential VGA has been fabricated in SMIC 0.18-μm CMOS process, and it only occupies 0.11 mm2. The measurements are in good agreement with simulation results. Experimental results show that the gain of VGA changes from 6.17 to 43.75 dB with a gain step of 3 dB. The high-pass comer frequency and low-pass comer frequency are around 0.22 Hz and 7.9 kHz, respectively. For each gain configuration, a maximal THD of 0.13% is obtained. The fully differential VGA has a low THD and its key performance parameters are well satisfied with the demands of ECG acquisition system application in the UWB wireless body area network.

A novel fully differential telescopic operational transconductance amplifier

A novel fully differential telescopic operational transconductance amplifier （OTA） is proposed. An additional PMOS differential pair is introduced to improve the unit-gain bandwidth of the telescopic amplifier. At the same time, the slew rate is enhanced by the auxiliary slew rate boost circuits. The proposed OTA is designed in a 0.18 μm CMOS process. Simulation results show that there is a 49% improvement in the unit-gain bandwidth compared to that of a conventional OTA; moreover, the DC gain and the slew rate are also enhanced.

A monolithic,standard CMOS,fully differential optical receiver with an integrated MSM photodetector

This paper presents a realization of a silicon-based standard CMOS,fully differential optoelectronic integrated receiver based on a metal–semiconductor–metal light detector（MSM photodetector）.In the optical receiver, two MSM photodetectors are integrated to convert the incident light signal into a pair of fully differential photogenerated currents.The optoelectronic integrated receiver was designed and implemented in a chartered 0.35μm, 3.3 V standard CMOS process.For 850 nm wavelength,it achieves a 1 GHz 3 dB bandwidth due to the MSM photodetector’s low capacitance and high intrinsic bandwidth.In addition,it has a transimpedance gain of 98.75 dBΩ, and an equivalent input integrated referred noise current of 283 nA from 1 Hz up to–3 dB frequency.

A Comparison Theorem for Solution of the Fully Coupled Backward Stochastic Differential Equations

The comparison theorems of solutions for BSDEs in fully coupled forward-backward stochastic differential equations (FBSDEs) are studied in this paper, here in the fully coupled FBSDEs the forward SDEs are the same structure.

Near-Relaxed Control Problem of Fully Coupled Forward-Backward Doubly System

In this paper,we are concerned with an optimal control problem where the system is driven by a fully coupled forward-backward doubly stochastic differential equation.We study the relaxed model for which an optimal solution exists.This is an extension of initial control problem,where admissible controls are measure valued processes.We establish necessary as well as sufficient optimality conditions to the relaxed one.

An OTA-C filter for ECG acquisition systems with highly linear range and less passband attenuation

A fifth order operational transconductance amplifier-C （OTA-C） Butterworth type low-pass filter with highly linear range and less passband attenuation is presented for wearable bio-telemetry monitoring applications in a UWB wireless body area network. The source degeneration structure applied in typical small transconduc- tance circuit is improved to provide a highly linear range for the OTA-C filter. Moreover, to reduce the passband attenuation of the filter, a cascode structure is employed as the output stage of the OTA. The OTA-based circuit is operated in weak inversion due to strict power limitation in the biomedical chip. The filter is fabricated in a SMIC 0.18-μm CMOS process. The measured results for the filter have shown a passband gain of -6.2 dB, while the -3-dB frequency is around 276 Hz. For the 0.8 Vpp sinusoidal input at 100 Hz, a total harmonic distortion （THD） of-56.8 dB is obtained. An electrocardiogram signal with noise interference is fed into this chip to validate the function of the designed filter.