A Fully Integrated, Low Noise and Low Power BiCMOS Front-end Readout System for Capacitive Detectors

Bipolar transistors are interesting for low noise front-end readout systems when high speed and low power consumption are required. This paper presents a fully integrated, low noise front-end design for the future Large Hadron Collider (LHC) experiments using the radiation hard SOI BiCMOS process. In the present prototype, the input-referred Equivalent Noise Charge (ENC) of 990 electrons (rms) for 12 pF detector capacitance with a shaping time of 25 ns and power consumption of 1.4 mW/channel has been measured. The gain of this front-end is 90 mV/MIP (Minimum Ionisation Particle: 1 fC) with non-linearity of less than 3% and linear input dynamic range is MIP. These results are obtained at room temperature and before irradiation. The measurements after irradiations by high intensity pion beam with an integrated flux of pions/cm² are also presented in this paper.     

Orthogonal cycle transforms of stochastic matrices

In this paper we investigate new Fourier series with respect to orthonormal families of directed cycles , which occur in the graph of a recurrent stochastic matrixP. Specifically, it is proved thatP may be approximated in a suitable Hilbert space by the Fourier series . This approach provides a proof in terms of Hilbert space of the cycle decomposition formula for finite stochastic matricesP.     

Can One Control the Vibrations of a Drum?

This paper considers the problem of constructing feedback stabilizing controllers for the wave operator on ⁿ (more generally AR systems determined by a hyperbolic operator). In order to accomplish this, it must first clarify the notion of an input-output structure on a distributed system, as well as what it means to interconnect two such systems. Both these notions are shown to be consequences of a structure which generalizes the standard causal structure of lumped systems determined by the flow of time. Given this apparatus, the paper then constructs feedback controllers which stabilize the wave equation along directions given by a proper cone in ⁿ.     

Finite-Memory Systems

Let K be a field, k and n positive integers and let matrices with coefficients in K. For any function

Decentralized \mathcal{L}_{2}–\mathcal{L}_{\infty} Filtering for Interconnected Markovian Jump Systems with Delays

This paper deals with the problem of decentralized $\mathcal{L}_{2}$ – $\mathcal{L}_{\infty}$ filtering for a class of interconnected (or large-scale) Markovian jump systems with constant time delays. The purpose is to present delay-dependent conditions for the existence of mode-dependent decentralized filters, which guarantees that the filtering error system is stochastically stable with a prescribed $\mathcal{L}_{2}$ – $\mathcal{L}_{\infty}$ disturbance attenuation level. Such a purpose is achieved by using a mode-dependent centralized Lyapunov functional together with the so-called Jensen’s inequality. The obtained synthesis conditions are expressed in terms of linear matrix inequalities (LMIs), which leads to a convex design method for the concerned filters. An example including numerical and simulation results is provided finally to illustrate the effectiveness of the proposed design method.     

Extended Robust \mathcal{H}_{2} and \mathcal{H}_{\infty} Filter Design for Discrete Time-Invariant Linear Systems with Polytopic Uncertainty

This paper is concerned with the problem of robust $\mathcal{H}_{2}$ and $\mathcal{H}_{\infty}$ filter design for discrete-time linear time-invariant systems with polytopic parameter uncertainties. Less conservative robust $\mathcal{H}_{2}$ and $\mathcal{H}_{\infty}$ filter design procedures are proposed in terms of single-parameter minimization problems with linear matrix inequality constraints. To this end, we generalize the filter structures available in the literature to date in such a way that the filter’s next state is built by summing the filter’s states over several samples from the past to the present. For stability of the filtering error system, the homogeneous polynomial parameter-dependent Lyapunov functions are employed. Finally, illustrative examples are given to demonstrate the merits of the proposed methods.     

A Note on Constant-Round Zero-Knowledge Proofs of Knowledge

In this note, we show the existence of constant-round computational zero-knowledge proofs of knowledge for all $\mathcal {NP}$ . The existence of constant-round zero-knowledge proofs was proven by Goldreich and Kahan (Journal of Cryptology, 1996), and the existence of constant-round zero-knowledge arguments of knowledge was proven by Feige and Shamir (CRYPTO, 1989). However, the existence of constant-round zero-knowledge proofs of knowledge for all $\mathcal {NP}$ is folklore, to the best of our knowledge, since no proof of this fact has been published.     

Optimizing CMOS Transconductor-C Filters for Low Power Wide Band Operation

A novel figure of merit to describe the bandwidth power efficiency of CMOS transconductors— is proposed and optimized for cross-coupled differential pair transconductor structures. The optimization is done in two different ways: univariable unconstrained and multivariable constrained. It is revealed that not only dc biases but also ac input phases can affect the bandwidth power efficiency of the transconductor. The bias voltages which can lead to best ratio at different ac phase combinations are obtained and presented in the article. HSPICE simulations are conducted to verify the theoretical predictions. On the basis of the cross-coupled differential pair transconductor, a biquadratic transconductor-C filter configuration is implemented. The frequency vs. power characteristic of the filter is studied for both optimally- and non-optimally-biased transconductor. It is shown that the optimization of the transconductor structure can result in performance improvement of the transconductor-C filter. The deviation of the optimal bias condition between the transconductor alone and the transconductor-C filter due to the inclusion of peripheray circuitries in the filter is discussed in the article.     

Linear systems in a saturated mode and convergence as gain becomes large of asymptotically stable equilibrium points of neural nets

We study solutions of the linear system in a saturated mode

An Accurate Performance Analysis for Regenerative Multi-hop Relaying in Wireless Networks Over Composite Multipath/Shadowed Fading

This paper presents and evaluates the performance of wireless networks that utilize the decode-and-forward relay. This multi-hop relaying scheme communicates over Extended Generalized-\({\mathcal {K}}\) (\(\hbox {EG}{\mathcal {K}}\)) composite fading channels to create performance evaluation. To this effect, new exact and easy to compute formulas for several performance metrics are derived. More specifically, new and exact-form mathematical formulas are derived for the cumulative distribution function, the generalized moments of the overall end-to-end signal-to-noise ratio, the outage probability (\({\hbox {P}}_{\text{out}}\)), the ergodic capacity (\({\mathcal {C}}_{\text{Ergodic}}\)), the moment generating function, and the average error probability (\({\hbox {Pr(e)}}\)) for different modulation schemes. Moreover, we carried out a series of computer simulation experiments in order to testify the accuracy of the derived framework. Finally, we discussed the impact of different parameters including fading/shadowing parameters, transmitted power and the number of hops on the derived expressions.     

Multiresolution approximation scale and time-shift subspaces

Multiresolution Approximation subspaces are -subspaces defined for each scale over all time shifts, i.e., “scale subspaces”, while with respect to a given wavelet, the signal space not only admits orthogonal scale subspaces basis, but orthogonal “time shift subspaces” basis as well. It is therefore natural to expect both scale subspaces and time shift subspaces to play a role in Wavelet Theory and, in particular, in Multiresolution Approximation as well. This is what will be discussed in the paper.     

Key-Dependent Message Security: Generic Amplification and Completeness

Key-dependent message (KDM) secure encryption schemes provide secrecy even when the attacker sees encryptions of messages related to the secret-key sk. Namely, the scheme should remain secure even when messages of the form f(sk) are encrypted, where f is taken from some function class $\mathcal{F}$ . A KDM amplification procedure takes an encryption scheme which satisfies $\mathcal{F}$ -KDM security, and boosts it into a $\mathcal{G}$ -KDM secure scheme, where the function class $\mathcal{G}$ should be richer than $\mathcal{F}$ . It was recently shown by Brakerski et al. (TCC 2011) and Barak et al. (EUROCRYPT 2010) that a strong form of amplification is possible, provided that the underlying encryption scheme satisfies some special additional properties. In this work, we prove the first generic KDM amplification theorem which relies solely on the KDM security of the underlying scheme without making any other assumptions. Specifically, we show that an elementary form of KDM security against functions in which each output bit either copies or flips a single bit of the key (a.k.a. projections) can be amplified into KDM security with respect to any function family that can be computed in arbitrary fixed polynomial-time. Furthermore, our amplification theorem and its proof are insensitive to the exact setting of KDM security, and they hold in the presence of multiple-keys and in the symmetric-key/public-key and the CPA/CCA cases. As a result, we can amplify the security of most known KDM constructions, including ones that could not be amplified before. Finally, we study the minimal conditions under which full-KDM security (with respect to all functions) can be achieved. We show that under strong notion of KDM security, the existence of fully homomorphic encryption which allows to encrypt the secret-key (i.e., “cyclic-secure”) is not only sufficient for full-KDM security, as shown by Barak et al., but also necessary. On the other hand, we observe that for standard KDM security, this condition can be relaxed by adopting Gentry’s bootstrapping technique (STOC 2009) to the KDM setting.     

On the distance to the instability border of hurwitz polynomials with coefficients that depend affinely onm parameters and a particular convexity property ofH n

Let

The Design of a 2-V 900-MHz CMOS Bandpass Amplifier

A 900 MHz low-power CMOS bandpassamplifier suitable for the applications of RFfront-end in wireless communication receiversis proposed and analyzed. In this design, thetemperature compensation circuit is used tostabilize the amplifier gain so that theoverall amplifier has a good temperaturestability. Moreover, the compact tunablepositive-feedback circuit is connected to theintegrated spiral inductor to generate thenegative resistance and enhance its value. The simple diode varactor circuit isadopted for center-frequency tuning. These twoimproved circuits can reduce the powerdissipation of the amplifier. An experimentalchip fabricated by 0.5 mdouble-poly-double-metal CMOS technologyoccupies a chip area of ; chip area. The measuredresults have verified the performance of thefabricated CMOS bandpass amplifier. Under a2-V supply voltage, the measured quality factoris tunable between 4.5 and 50 and the tunablefrequency range is between 845 MHz and 915 MHz. At , the measured is 20 dB whereas thenoise figure is 5.2 dB in the passband. Thegain variation is less than 4 dB in the rangeof 0–80^°C. The dc powerdissipation is 35 mW. Suitable amplifier gain,low power dissipation, and good temperaturestability make the proposed bandpass amplifierquite feasible in RF front-endapplications.     

BIBO Stability of D-Dimensional Filters

Consider the class of d-dimensional causal filters characterized by a d-variate rational function analytic on the polydisk . The BIBO stability of such filters has been the subject of much research over the past two decades. In this paper we analyze the BIBO stability of such functions and prove necessary and sufficient conditions for BIBO stability of a d-dimensional filter. In particular, we prove if a d-variate filter H(z) analytic on has a Fourier expansion that converges uniformly on the closure of , then H(z) is BIBO stable. This result proves a long standing conjecture set forth by Bose in [3].     

A Symbolic Circuit Analysis-Oriented Algorithm for Finding a Common Tree of the Current and Voltage Graphs

A fundamental problem of symbolic analysis of electric networks when using the signal-flow (SFG) graph method is to find the common tree of the current and voltage graph ( and , respectively). In this paper we introduce a novel method in order to determine a common tree of both graphs, which may be used to obtain the symbolic network transfer function when carrying out the small-signal analysis of linear(ised) circuits.     

A Small Area Charge Sensitive Readout Chain with a Dual Mode of Operation

A charge sensitive readout chain has been designed and fabricated in acommercially available 0.8 m CMOS technology. The readout chain is optimizedfor pixel detectors measuring soft X-ray energies up to 20 KeV. In the first modean analog signal proportional to input charge is generated and processed in realtime. In the second mode a peak-and-hold operation is enabled and therelevant signal is processed in later time. This dual mode of operation iscontrolled by an external digital signal. The readout chain consists of a chargeamplifier, a shaper, an operational amplifier which can either operate as avoltage amplifier or a peak detector and an output buffer. Its area is . The gain at the shaper output is 378 mv/fC, theENC is 16 rms at 160 nsec shaping time. The overall gainis 557 mV/fC, the ENC is rms with 240 nsec peaking timeand 1.4 sec recovery time. The overall power dissipation is 1.5 mWatt with aload capacitance of 25 pF.