IEEE Transactions on Circuits and Systems I: Regular Papers

An 11.75-Gb/s combined decision feedback equalizer (DFE) and clock data recovery circuit in a 0.18-μm CMOS is presented. Various techniques are applied to reduce the chip power consumption. In particular, the feedback path of the DFE is merged with an Alexander phase detector (PD). An analysis on the speed requirements of various blocks in the PD and DFE circuits is performed to determine the opti... View full abstract»

A recently introduced power-combining scheme for a Class-E amplifier is, for the first time, experimentally validated in this paper. A small value choke of 2.2 nH was used to substitute for the massive dc-feed inductance required in the classic Class-E circuit. The power-combining amplifier presented, which operates from a 3.2-V dc supply voltage, is shown to be able to deliver a 24-dBm output pow... View full abstract»

The focus in this paper is on the extraction of RF circuit performance characteristics from the dc output of an on-chip temperature sensor. Any RF input signal can be applied to excite the circuit under examination because only dissipated power levels are measured, which makes this approach attractive for online thermal monitoring and built-in test scenarios. A fully differential sensor topology i... View full abstract»

A dual-operation-mode ring oscillator that employs dual-delay paths is presented. The two operation modes, referred to as the differential and common modes, have different output waveform characteristics and oscillation frequencies. A nonlinear model for the dual-delay-path ring oscillator and the analysis of the stability of each operation mode are proposed to confirm both simulation and measurem... View full abstract»

We propose a resonant parametric amplifier with an enhanced noise performance by exploiting the noise-squeezing effect. Noise squeezing occurs through the phase-sensitive amplification process and suppresses one of the two quadrature components of the input noise. When the input signal is only in the direction of the nonsuppressed quadrature component, squeezing can lower that noise figure by almo... View full abstract»

This paper presents a new state-space formulation of the frequency transformation of linear continuous-time systems. We call this formulation “Gramian-preserving frequency transformation,” which enables us to convert a given prototype state-space system into other systems that have the same controllability/observability Gramians as those of the prototype system. As a practical application of this ... View full abstract»

This paper presents a sub-Nyquist rate sampling receiver architecture that exploits signal sparsity by employing compressive sensing (CS) techniques. The receiver serves as an analog-to-information conversion system that works at sampling rates much lower than the Nyquist rate. A parallel-path structure that employs current mode sampling techniques is used. The receiver performance is quantified a... View full abstract»

A method for evaluating the available energy (as defined in 1981 by Wyatt ) of the proper linear lumped time-invariant passive one-ports of any order is proposed. The devised approach borrows many tools and techniques from the calculus of variations (Euler-Lagrange equations and natural transversality conditions). However, the final formula of the available energy has the simple structure of a qua... View full abstract»

Processor manufacturers use advances in manufacturing technologies to increase the number of cores on chip in order to scale performance in a cost-efficient manner. As the number of cores scales up, not all cores can be directly connected to the main memory and there is a need for hierarchy, for example, by arranging them in clusters that share L2 caches. This paper focuses on designing cost-effic... View full abstract»

This paper introduces reconfigurable nonuniform transmultiplexers (TMUXs) based on fixed uniform modulated filter banks (FBs). The TMUXs use parallel processing where polyphase components, of any user, are processed by a number of synthesis FB and analysis FB branches. One branch represents one granularity band, and any user can occupy integer multiples of a granularity band. The proposed TMUX als... View full abstract»

This paper proposes an efficient structure for implementing a linear-phase finite-impulse-response (FIR) filter of an arbitrary order N for the sampling-rate conversion by a rational factor of L/M , where L(M) is the integer upsampling (down-sampling) factor to be performed before (after) the actual filter. In this implementation, the coefficient symmetry of the linear-phase filter is exploited as... View full abstract»

In this paper, we propose a new reciprocal-orthogonal parametric discrete Fourier transform (DFT) by appropriately replacing some specific twiddle factors in the kernel of the classical DFT by independent parameters that can be chosen arbitrarily from the complex plane. A new class of parametric unitary transforms can be obtained from the proposed transform by choosing all its independent paramete... View full abstract»

In this paper, a relationship is discussed between three common assumptions made in the literature to prove local or global asymptotic stability of the synchronization manifold in networks of coupled nonlinear dynamical systems. In such networks, each node, when uncoupled, is described by a nonlinear ordinary differential equation of the form ẋ =f(x,t) . In this paper, we esta... View full abstract»

This paper presents a framework for global synchronization of dynamical networks with nonidentical nodes. Several criteria for synchronization are given using free matrices for both cases of synchronizing to a common equilibrium solution of all isolated nodes and synchronizing to the average state trajectory. These criteria can be viewed as generalizations of the master stability function method f... View full abstract»

This paper evaluates the security of the generalized chaotic convolutional coder, which is a recently proposed joint error-correction and encryption scheme integrating the chaotic encryption into the convolutional coding. Our results show that the probability of fully recovering the pseudorandom sequence (PRS) controlling the chaotic switches is at least 0.289 under known-plaintext attack, if the ... View full abstract»

The design of power-efficient orthogonal frequency division multiplexing (OFDM) transmitters suffers from a major bottleneck due to the high peak-to-average ratio (PAR) of OFDM signals as the efficiency of a linear RF power amplifier (PA) reduces drastically due to backoff requirements. In this paper, we propose a system-level approach for dynamic power reduction in OFDM transmitters with varying ... View full abstract»

This paper proposes a small-signal model for variable-switching-frequency hysteretic converters operating in continuous conduction mode (CCM) and discontinuous conduction mode (DCM). The model is capable of predicting flip-bifurcation phenomena when the hysteretic converter operates below the CCM/DCM boundary. By developing a discrete-time state-space model of the converter, the z-domain model is ... View full abstract»

Wireless transmission systems fed by ambient harvested energy power sources can operate continuously, without needing battery replacement. Such systems are ideal for applications with limited or difficult accessibility. Ambient energy sources exhibit a stochastic nature, so an energy storage device must store the harvested energy. In this work, a control method that minimizes the use of storage is... View full abstract»